MTG Salvation

1 CMC:
Soul Warden/Soul's Attendant - The namesake and engine of the deck. The may on Attendant is mostly irrelevant thanks to a recent rule change, but it can still come in handy. Decks with as few as 6 of the one drop sisters have posted results, but you probably want 4 of each.
Serra Ascendant - Having a 6/6 flying, lifelink creature on turn 2 is the most unfair thing the deck can do, and sometimes you have to fight unfair with unfair. While it’s possible to send her up in the air without a Martyr activation, you’ll lose some of her explosive ability to shut down a game without Martyr.
Martyr of Sands - She’s still not a great top deck, but when the format is fast and explosive, she is our best way to have a game-ending threat on turn two. She’s also very easy to fetch and recur. Run 2-3, unless you’re multi-colored or trying to bring in artifacts.
Doomed Traveler - Two creatures (therefore two triggers) plus a flyer is an interesting proposition, but there’s rarely room for this little guy in the deck.
Champion of the Parish - Every sister, as well as Serra, triggers him. Sadly, he rarely does well in strictly mono-white build, as you have to cast him turn 1 to be relevant.
Figure of Destiny/Student of Warfare - These don't do much with our strategy but are beat sticks we can fetch with Ranger. Run one if you run any.

2-3 CMC
Ajani's Pridemate - This deck's Tarmogoyf. It's a lightning rod for removal and it has no built-in evasion, but it is still one of the best ways to kill your opponents with the deck. If it stays on the board with a sister or two, your opponent is out. Run 4.
Auriok Champion - When Death's Shadow is the best deck in the format, she's a rockstar. She blanks all of their threats in Grixis and can still blank a Dark Confidant all of Burn's creatures and most of Dredge's while dodging Bolt and Push. Two is nice, three is better in a burn- or BGx- heavy meta.
Squadron Hawk - Caw! Some decks still lean on this birdy to stop dangerous flyers (particularly Inkmoth Nexus, but there’s still not much room in the deck for a four-of with diminishing returns. Too often, it’s just an expensive chump blocker, which we get more from when we can get the same number of bodies from one card and 3 less mana (Lingering Souls)
Ayli, Eternal Pilgrim - She’s just on the fence of playable in some builds, because that repeatable Vindicate is often what the deck needs and is very good at crawling out from under a board stall. Obviously, she requires a black splash, but if you’re already running the 8+ token generators the black versions of the deck run, you can try one or two in your 75.
Thalia's Lieutenant One part Honor of the Pure, one part Ajani’s Pridemate. It can add some flexibility to the deck, but starting off with one toughness and only giving the buff when it enters the battlefield can make it a tough sell in red-heavy metas. 2-3 is the number most people are settling on, but you’re probably better off using this in a dedicated Humans deck.
Serene Steward - Turning every creature into a Pridemate is nice, but the mana commitment is a little high. You also have to use her ability on her a few times to keep her alive. Not worth running in most builds.
Suture Priest - Not worth running unless you're on a hyper budget build.

3+ CMC
Ranger of Eos - One of the only ways the deck generates card advantage. Gets very bad if you only run the one-drop sisters, and becomes amazing if you run some number of Martyrs. 2-3 is the right number in most circumstances.
Archangel of Thune - Running her means increasing your lands from 19-21 to 22-23, which is a lot. However, her ability to completely shift the game in your favor the minute she hits the board cannot be denied. Going Sister, Thune, Token Generator is almost impossible for decks to come back from.
Mentor of the Meek - Much better on paper than in practice. Forces you to hold back from casting creatures, and most of the creatures we want to cast in the later turns either won't trigger it or will trigger it but won't allow us to leave mana open to get the cards we want.
Felidar Sovereign - The last thing the deck needs is a 6-drop when we want the game over by the time we hit 5 mana. The life total isn’t as easy to get to you as you might think and it will most likely not survive to your upkeep, anyway.

Instants and Sorceries:
Path to Exile - The best removal spell for the deck. Many of our creatures are easy to lose, so it sometimes becomes helpful to use this as a way to hit Ranger or Archangel mana. Run the full 4, even if you sideboard some.
Spectral Procession - Amazing value at 3, great value at 4, not impressive at 5-6. We'll can often hit it for 3 on turn 3, which is good for 3-6 life and a 6/6 Pridemate. The playset is fantastic, and you'll want to draw them all day in almost every match up.
Lingering Souls - Requires at least a few Isolated Chapels to get maximum value, but remember that this card can just win the game on its own. 4 Tokens over 2 turns, or the ability to hit five mana and just dump 4 creatures onto the board is a must-answer threat for our opponent that triggers a sister often enough to make an impact.
Secure the Wastes - It's an impressive topdeck in the late game and is worth the cost at every number except 2-3CMC. Being able to drop an army of tokens at instant speed gives our linear deck a "Gotcha!" 1-2 is enough if you can find room.
Zealous Persecution :rate 3.5: - A good way to make Wraths less brutal for us is to make them one-sided, instant speed, and only cost two mana. This can wreck Infect, Bogles, and Tokens or also just help us punch in extra damage when we are close to the win. Black splashes can safely main 1-2.
Proclamation of Rebirth/Return to the Ranks - Some people turn to these cards in sweeper heavy metas to bring back a ton of Sisters or a Pridemate, usually at once. Return to Ranks is more flexible and is typically the better choice by a large margin. 2-3 is the right number if you want to use these.
Brave the Elements - Though this is probably a sideboard card, some people like it enough to run it main deck. Simply saying no to a Pyroclasm or Anger of the Gods is delicious, and it's even nicer when you can give Pridemate some much needed evasion. Consider 1-2 somewhere in your 75.
Orzhov Charm - In Martyr-heavy builds, this can get Serra in the air or get her back on the board when you’re already at 30. Even if you don’t run Martyr, you’ll usually have a target. Both of its other abilities are relevant (the destroy ability is just 2-mana Murder for us, and bouncing a Ranger or removal target back to your hand for value is fine.) It’s probably best as a 1-of.

Enchantments/Artifacts
Honor of the Pure - A 1/1 is very easy to kill and very hard to kill with. Our deck is full of them, so something that buffs them not only makes us more of a threat to kill our opponents, it makes us stronger against Electrolyze, Pyroclasm, and other damage-based removal. Token generators in conjunction with this become very, very terrifying.
Oblivion Ring - Catch-all removal is good and enchantment hate is fairly rare, but this is still sideboard material in most builds.
Aetherflux Reservoir - There will absolutely be games where you catch someone with this and it turns itself on a lot better than stuff like Felidar, but 50 life is a lot even for us and if you're there, you're already winning. This is a dead card far too often to merit consideration.

Planeswalkers:

Typically, we want walkers that generate creatures and then either buff those creatures or reward us for playing those creatures. Of the walkers available to us, Elspeth and Sorin (if you're in black) are the best at this, Gideon is getting surprisingly good at it, and Ajani typically doesn't do it well.

Gideon, Ally of Zendikar - We are win condition light, so a 5/5 for 4 that can also shoot out a creature or buff our team seems very good on first glance. He checks all the boxes, as he survives a Bolt after you cast him, can protect himself with a creature and can generate a clock in two ways (His own or just by turning into an Honor of the Pure if you went sister, sister, Spectral.
Gideon of the Trials - The "ultimate" is really, really powerful for a deck that gets destroyed by combo, especially when most combo will struggle to kill him. 3-mana is a very friendly price to pay for a beater that also lets us stop people from pressuring us and win a race.
Elspeth, Knight-Errant - All three of her abilities are relevant for us. Unfortunately, she doesn't really generate as much value as you might expect. She's best for giving Pridemate evasion or helping Serra Ascendant turn itself on. Consider 1-2 if you have room.
Sorin, Solemn Visitor - If we follow the curve, turn 1 Sister, turn 2 Pridemate, turn 3 Spectral, turn 4 this would be a nut draw. Even if you just use him to generate two tokens, he's about worth the cost.
Elspeth Tirel - Very costly, but explosive if she lands. She can wipe the board and turn the game almost instantly, or just generate creatures onto an empty board. If you're already running Archangel and have the mana to support her, she's worth considering.
Kytheon, Hero of Akros - We can hit that trigger readily, and if we do we get a 4/4 that can give our creatures pseudo-vigilance and make them indestructible. If he’s paired with Archangel, Pridemate or Serra, that can be scary. Even if he doesn’t flip, a 2/1 for 1 is often okay for us if we just need to bash in.
Ajani, Caller of the Pride - Similar to Elspeth, but can't generate his own creatures for the abilities to be relevant.
Elspeth, Sun's Champion - Often too slow and hits our best creatures with her board wipe ability. She's made for grindy control decks which we most certainly are not. Don't run.

Plains: If you like your lands to match, you should invest in about 12-18 of the same art. That's about how many you'll run, depending on your build.
Ghost Quarter: In matches like Infect and Tron, this becomes our only hope of winning. It also has application against any deck that runs creature lands and a good way to kill a Desolate Lighthouse or Valakut. Consider the full playset, but run at least 3.
Windbrisk Heights: Not mandatory, but can help add some explosiveness to our deck. We can hit three creatures attacking pretty easily, and this card allows us to play a discounted Archangel or Spectral, or an Honor of the Pure at instant speed. The full playset can lead to some awkward draws/slower hands, but 2-3 is easy to manage.
Flagstones of Trokair: Awkward if they maindeck Blood Moon or you use Rest in Peace from the sideboard, but a great way to get extra value out of Ghost Quarter. When you fetch, you can search out a shock land or a Mistveil Plains.
Cavern of Souls: Definitely a budget buster and only provides a small advantage against a small handful of decks, but if you're taking the deck to a serious tournament, it merits consideration. There are many builds where this makes just about every creature except Pridemate uncounterable
Mistveil Plains: Usually not worth it unless you run Squadron Hawk. Then, it's okay at 1 or 2. Never run 3 or more.

Depending on how many lands you run, you have anywhere from a 35% (20 land builds) to a 42% chance (23 land builds) of drawing a land after keeping your one lander. Based on those stats, you may not see your next land until your third or fourth draw (or later if you have really terrible luck). That means the most important decision when looking at a one land hand is "Does it have Path to Exile?" You need to be able to Path something on turn 2 or 3, so keeping a risky hand that doesn't have the Path panic button is asking combo to go off on you or Tarmogoyf to run you over.

An ideal one-land hand that I would snap keep every time would be:



You're eventually going to draw that second land, and it doesn't matter what it is with this hand. Replace that Pridemate and Honor of the Pure with an Auriok Champion and then imagine yourself drawing a Ghost Quarter as your second land. Feels really bad, doesn't it? You're even less likely to keep a one lander that has even a single Spectral Procession, Ranger of Eos or Archangel of Thune.

Situations:

• If I see more than one card that isn't a one-drop or a two drop with a generic mana cost in my hand with only one land, I send it back. (Just one three-drop or higher is functionally the same as mulliganing down to six.)
• If I'm running Martyrs and my opening hand is full of them instead of Sisters, I send it back (A good player will Lightning Bolt your turn one Martyr and keep doing it if you don't draw the second land.)
• If my one land is a Windbrisk Heights, I send it back. It's a good bet you're going to see 1-3 lands off a Windbrisk activation, which is miserable when you need to draw those.

This is where I ideally want to be. The only way I send back a two or three lander is if:

• Neither land produces White mana
• I have a handful of Ranger of Eos, Archangel of Thune or Spectral Procession and no turn one or turn two play. (This is often fine to keep, though)
• The hand doesn't have anything but sisters (And I'll keep this in a handful of match ups, as well.)

4 lands is a hard number, but it does make casting Ranger of Eos or Archangel of Thune on time easy. I'll keep this if I know I'm facing a slow match up and the three spells are:

• Sister, Pridemate, and a game-changing threat (RoE, AoT, Spectral).
• Sister, two game-changing threats.
• Token generator with at least one Honor of the Pure.

Do not make the mistake of keeping that Sister, Sister, Pridemate hand. A turn one Thoughtseize will end the game.

Burn - Burn usually can't beat lifegain, which is exactly what our deck does. It's not an auto-win like most people imagine (they can occasionally be too fast for us), but it's pretty close. If you plan on gaining a big chunk of life, make sure they don't have Skullcrack/Atarka's Command mana up. Know they will sideboard hard for you and don't keep risky hands. (Sideboard to consider: Don’t ignore your sideboard - they hate us hard post board and we have cards that lock them out likeLeyline of Sanctity, anti-combo cards, and Kor Firewalker Something to kill Blood Moon might be helpful against mono-red varieties, as well.)
Hatebears/D&T - - In most situations, their hate doesn’t affect us as much as it does other decks. Their idea of getting “big” isn’t as stressful to deal with it as other decks, and they’re a little slow. They can get the better of us as the game goes long, but we can usually race through them. Make sure you keep hands that have some form of flying creatures, otherwise they might get you in the air. (Sideboard to consider: Shutting down Vial with artifact hate or Stony Silence helps. A well-timed Wrath of God can hurt them badly. They do most of their damage in the air, so ways to stop that (Sunlance, more token creatures) can be wonderful.
Death's Shadow - Their commitment to hurting themselves combined with our ability to get wide and big puts them on the ropes against even some of our bad hands. Our lifegain means they can't feasibly kill us without pump until turns 5 or 6, which is about the time we can have a giant creature or tokens + honor to finish off the life they have left. Although they run enough spot removal to slow us down, we should win the race consistently. (Sideboard to consider: Celestial Purge and/or Blessed Alliance should come in as extra paths (Blessed Alliance can be a two-for-one if you give them the life when they attack with two Death's Shadows or if you untap a Pridemate to kill a Goyf.), Worship/Ghostly Prison are okay if the game runs a little long, Rest in Peace could be okay but YMMV because only some of them rely on the graveyard (against Jund it shrinks Goyfs, against Grixis it might stop a Tasigur or Snapcaster, against Esper it could catch a Lingering Souls.)
Affinity - - Our mission is to get bigger than them or wider than them quickly. It's not the easiest thing to do without a Martyr into Serra in game one, but it's possible. It's very obvious what to Path at all times. Kill their Inkmoth Nexus at any cost. Game 2&3 get much, much easier as we can just hate their entire strategy with our sideboard and then slowly pound them into dust. (Sideboard to consider: Stony Silence is mandatory and shuts them down almost instantly. Artifact kill targets just about everything in their deck. Suppression Field can behave like a Stony Silence for some of their cards, as well. [card]Ghostly Prison[card] with chump blockers is hilarious against them.)
Dredge - - Between our ability to get bigger than them, their ability to lose to themselves, and having the best graveyard hate in the format, this matchup can go our way a lot of the times. Try to path anything that Pridemate and Serra can’t trade with and fly overhead once they’ve gassed themselves out. (Sideboard to consider: Rest in Peace is obviously incredible. Wrath effects can shut them down, but exiling effects like Celestial Purge are better. A Surgical Extraction in response to their effects can get their best creatures out of the deck. Hallowed Moonlight can exile a card and make them waste a turn while giving us much-needed card draw.
Merfolk - - We have plenty of game against decks that swarm the board thanks to our lifegain. While we don't have a ton of ways to answer the Islandwalk, as long as we can survive for a few turns and get a Pridemate or Serra up and running, we can win this matchup with a lot of consistency. (Sideboard to consider: Our best bet is to stop their swarm, so Wrath of God is a blowout and Ghostly Prison is hard for them to win through. Artifact hate for Aether Vial can be helpful, as is something to kill Spreading Seas.
BG/X The watermark test for your build, as it is split mostly right down the middle with a small variance. Auriok Champion can be an all-star, as are token generators that make Liliana of the Veil less valuable for them and make chumping or trading damage no problem. The trick is to make them answer you one for one until you can outvalue them, then make all of their good stuff less good post-board. (Sideboard to consider: Suppression Field hurts any activated abilities, which they have a lot of. Direct damage neutralizers (Mark of Asylum/Brave the Elements) are helpful. Leyline of Sanctity stops targeted discard, Bolts, and 2/3 of Liliana's abilities. Celestial Purge has tons of quality targets.)
Tron - - Eldrazi is about even and Blue is easier than R/G by a lot, but if they get their lands naturally, we're sometimes toast. Counter magic, discard and board sweepers wreck us, and that's how both of these decks get to the point of casting their big creatures. 4 Ghost Quarter can sometimes bring them into range for the kill, and Serra into Martyr is often the best way to kill them quickly. (Sideboard to consider: Don't make the mistake of bringing in stuff to kill the huge stuff they ramp into, just kill the ramp instead. Stony Silence, Suppression Field and even Sundering Growth can do that for you. Weathered Wayfarer can fetch your Ghost Quarters. Extirpate, if you're in black, allows you to keep them off of Tron forever on turn 2 (Use Quarter on a Tron land, then Extirpate the Tron land you just Quartered.
Storm & Other Combo - - Decks that can ignore everything we do and go off on turn 3 or 4 consistently are super bad for us. We can typically only win if we can kill them in that time, which is really difficult for us to do. Serra into Martyr can do it, but then they can just Lightning Bolt that away. Your goal is to hope they brick game one and then to hate them out in game 2 and 3.(Sideboard to consider: Leyline of Sancity is a mainstay for these decks. Rest in Peace stops the Pyromancer’s Acension and. If Storm tries to Empty the Warrens (which they will do post board expecting the Leyline,) Ghostly Prison can just get ‘em).
CoCo Combo - - Now that they are more interested in infinite mana than infinite life or damage, this matchup got a lot worse. We have to have multiple Paths to get them, but their inevitably will usually find a way. Apply consistent pressure, get rid of Vizier and Druid if you can, and hope for the best. (Sideboard to consider: While it’s easy to answer, Rest in Peace stops them from getting back CoCo. Leonin Arbiter/Aven Mindcensor can hurt them badly. Linvala, Keeper of Silence and Suppression Field shut down the infinite and make them just try to value you.)

Delver - - This deck is mostly concerned with counting to 20, which makes us hard for them. They are really wide open to Paths and we can trade damage and get there. (Sideboard to consider: The more fair you can make them, the easier it gets. Rest in Peace makes Snapcaster or Tarmogoyf a bear, Spellskite, Mark of Asylum, Brave The Elements, and Kor Firewalker make their removal package tough. Anti-combo cards can stop them from using all of those cards their drawing, as well.
Zoo - - Similar to Delver, though the Wild Nacatl unbanning hurts. One of the easiest ways to lose this is to not play smart. Know when you have a board state that can race them (and, therefore, don’t need to chump), and know when it’s safe to overextend (When you’ve run their hand down to a small range) Watch out for Bonfire of the Damned, though! (Sideboard to consider: Wrath of God goes boom against them. Brave The Elements is solid and better than Mark of Asylum (they get hurt badly from Pyroclasm and Anger of the Gods, so probably won't use them except for as a Hail Mary.) Ghostly Prison is gnarly.
Eldrazi - - The banning of Eye of Ugin turned this match up considerably in our favor. Their explosive starts are gone, which mean they are just going to play a big spell on turn 3, which we can ignore or Path. From there, treat it like a BGx deck that can't play as much removal and disruption. If you're facing the BW version, remember they can go wide on us suddenly and prepare accordingly. (Sideboard to consider: Depending on the build, Leyline of Sanctity can be either good or excellent. It turns off discard and stops their Relic nonsense. Oblivion Ring may be the best extra piece of removal (or Sundering Growth if you see Chalice), and a board wipe like Wrath of God does have a good amount of value.
Living End - - They’re slower than us, so we can often put a lot of pressure on them and force an early Living End. They’re forced to reanimate our stuff, which all has enter-the-battlefield triggers (Reanimating a Ranger is legitimately awful for them.) Our big creatures are a lot bigger than their big creatures. (Sideboard to consider: Obviously, Rest in Peace is strong. Wrath of God shuts them down after a Living End. A Brave The Elements can counter a Shriekmaw trigger and Suppression Field or Linvala, Keeper of Silence can hurt their plan to Fulminator Mage.
Goblins - - They can occasionally get us in a race, but we can typically survive their big hitters and swing back with enough power to wreck them. Auriok Champion is their worst nightmare and their lack of ways to refill once they empty their hand makes them a pushover. (Sideboard to consider: Wrath of God is a blowout, Leyline of Sanctity and Mark of Asylum force them to target their removal where you want it, Ghostly Prison can sometimes choke them from playing spells.
Spirits -rate3.5:- While control magic can be a giant pain, this deck likes to bounce things and swing over our heads, both of which is fine for us. We're a touch faster and have our own fliers to take care of theirs, all while buying time with our life gain. They sideboard for us well, though. (Sideboard to consider: Ghostly Prison is probably better than Wrath considering their countermagic and Selfless Spirit. Combo hosers that force them to play one spell at a time can stop their tricks. Blessed Alliance is oddly strong against them.
Knightfall - - Since this combo is slower than most Modern combos, we can often buy the time we need to take them down. They also can only make their Knight of the Reliquary so large – which means we can survive a hit or two from it in many cases. That isn’t to say the match is an easy walk, though – it is still a blue deck, so they have access to lots of counterspells that can often wreck us. Hold up Path as often as possible. (Sideboard to consider: More removal, usually in the form of Blessed Alliance does a lot of work here. Aven Mindcensor/ Leonin Arbiter stops their search. Rest in Peace turns Reliquary into a permanent 2/2. There are lots of ways to attack, but try not to over sideboard here.)
Grixis - - Control is rough for us, but this plays a lot like BG/x, so Spectral Procession and Auriok Champion can be all-stars in this match up. As long as you play correctly and don’t run yourself into counters or blow out removal, you can get there. The same general strategy of making them fight you fairly through 1-for-1s until you can get the upper hand applies here.(Sideboard to consider: Mark of Asylum/Brave the Elements hurts their Lightning Bolts and Kologhan’s Command. Rest in Peace is strong. Sunlance kills everything but the delve creatures.
Scapeshift - - This deck really wants to deal 18, which means we can mess with their math and get them. It gets harder if you don’t run Martyr, but getting your life total out of range is very possible. Post board, they can become a Tempo deck or a Titan deck, so they can be weird to battle. (Sideboard to consider: Aven Mindcensor in response to search effects can be a blowout. Leyline of Sanctity stops them from hurting you, and Spellskite eats Valakut, The Molten Pinnacle's damage, which can throw off their math. If they bring in an Inferno Titan, which they might, you can bring in Mark of Asylum or similar protection. Do not side out your all of your Paths just because of Sakura-Tribe Elder; You'll probably need them in games 2 or 3.
Blue Moon - - While we’re mostly immune to Blood Moon, this deck uses red and blue for a lot of counter and value-removal, which can slow us to a crawl. Remember that they’re the control deck, so try not to overextend into an Electrolyze, and try to bait the counters as much as you can. (Sideboard to consider: Bolts are a part of their plan, so Mark of Asylum can shine here as can Thalia, Guardian of Thraben. Rest in Peacefor Snapcaster can often be fine. Obviously, enchantment hate for the Vedalken Shackles and other artifact/enchantments they try to mess you up with can save the day.
B/W Tokens - - This deck is so much like us, but they use hand disruption like Thoughtseize and Inquisition of Kozilek instead of life gain to buy turns. Occasionally, they get going quicker than we do. It also gets more mileage out of Planeswalkers than we do and can overwhelm us in the air. We’re just as likely to get a big beater down to dispatch their guys, though. It’s really who gets the better hand. They often lose to a loaded Serra, since 6 life erases a lot of their damage. (Sideboard to consider: Leyline of Sanctity stops their discard, Ghostly Prison slows them considerably and Wrath of God always hurts them more than it hurts us. Destroying their anthems with enchantment hate is powerful.
Bogles - - Serra into Martyr can race them, but they can get lifelink and unblockable far too easily and quickly for us to combat in most situations. If you don't have a way to kill them by turn three in your opening hand, you've probably lost. (Sideboard to consider: Blessed Alliance is strong, Spellskite can eat their enchantments and Wrath of God is occasionally the best way to kill things. Obviously, Disenchant or Sundering Growth is useful, but not a blowout for them. Fracturing Gust is usually too slow, but Tempest of Light can get there consistently.
Elves - - This deck can go over our big life total and smack us. It’s typically too fast for us to stop unless you pop Serra into Martyr or have a really excellent Pridemate hand. They can and often do pack their own Sister (Essence Warden) somewhere in the 75 to slow us down. (Sideboard to consider: You need board wipes, even if Wraths can sometimes be too slow. Ethersworn Canonist and other combo hate can slow them down enough to make the fight fair. They're all in on the combo and sometimes can’t remove a Pridemate, so holding up a Brave The Elements for when he gets huge after they dump their hand can just get them. Planeswalkers that give evasion (Elspeth, Knight Errant or Ajani, Caller of the Pride) can do it, too. If your answer comes down after your fourth turn, it's a bad answer.)
Ad Naseum - - We're lucky that this deck can brick on itself. Game 1, your plan is to Martyr your way out of range of their Lightning Storm, then try to clock them out with beats. Game 2 and three, balancing your sideboard with quick beats to force them to waste their Phyrexian Unlife or Angel's Grace is key. (Sideboard to consider: Ethersworn Canonist/Eidolon of Rhetoric prevents them from drawing their deck. Removal for the Unlife and Stony Silence to stop the land rocks is solid. Avoid siding out too many of your fast beats; tokens usually aren't quick enough to kill them. If you're in Black, Thoughtseize/Extirpate is a house. )
RWx Kiki/Nahiri - - More token generators make it better, but they’re inevitability and giant creatures often take us down. Hold up Path whenever they have one Part of the Kiki/Resto win if you can, or just try to constantly Path their Restos. Don't make the mistake of spreading your removal out; Pick something and make sure they can never stick it for too long. Otherwise you will run out of Paths. (Sideboard to Consider: A few Celestial Purge and search hosers can keep Nahiri from being a huge problem while also being able to stop Kiki and Chord. Combo hate can occasionally hose them, Rest in Peace is fine to stop Snapcaster or force them to exile a discarded Emrakul in the late game. Suppression Field/Ghostly Prison kills the infinite combo.
Infect - It’s a really bad match up on paper, but don’t put yourself into a conceding mindset the minute you see it coming. It gets better with token generators and other ways to swarm the board on our side. Try to remove things on your turn so they have to waste their pump spells protecting things and for the love of everything, run Ghost Quarter! (Sideboard to consider: Remember – you shouldn’t side out your entire life gain package, it’s still your engine! Spellskite can eat their clock, which is fun. Anti-combo cards like Ethersworn Canonist or Thalia, Guardian of Thraben can slow them down, too. Blessed Alliance is powerful but can be awkward. Don’t forget that Inkmoth is an artifact and dies to the appropriate removal! Note: If you’re in Black, Turn one Thoughtseize is basically free and can make them stumble if they have to keep a tough hand.
Lantern - - The sad truth is our clock is too slow to not lose to an Ensnaring Bridge. We have to hope they don't find it to get to game 2, where we can fight them with sideboard. Unfortunately, they can just mill away your answers, so those answers have to come down before turn 3/4. It's a rough deck to play against, which makes things even more annoying. (Sideboard to consider: Leyline of Sanctity and Stony Silence are really worth it. Sundering Growth or something to kill the Ensnaring Bridge before they lay a second one is necessary. Enchantment/Artifact wrath effects look enticing, but often aren't necessary - the bridge is what stops us from winning. Avoid mashing your whole sideboard into your deck to stave off the mill, that actually decreases your chances of drawing the cards you need to win.)
Gifts/Reanimator decks - - Even when we splash colors, we are mostly a mono-white deck, meaning Iona, Shield of Emeria reads “We can’t play spells.” Elesh Norn, Grand Cenobite is often a board wipe on a 4/7, as well. We often just scoop game one and then struggle to do much game two and three unless we land Rest in Peace, which they will often blow up. Sideboard to consider: Rest in Peace shuts them down if they can’t answer it. Suppression Field and Linvala, Keeper of Silence are nice if they happen to hit Griselbrand. Our best sideboard here is that the deck is not very popular.

Combo Hate:
Thalia, Guardian of Thraben, Eidolon of Rhetoric, Ethersworn Canonist, Rule of Law.

These are good against decks that look to dump their hand on a single turn, including Storm, Ad Naseum, Burn, Infect, Elves. Worth considering for their ability to hate on cantripping decks like Grixis and UW Control, as well. 2-3 of your favorite is worth it.

Graveyard Hate:
Rest in Peace, Relic of Progenitus, Tormod’s Crypt, Grafdigger’s Cage, Dryad Militant

There are others, but these are usually the best, with Rest in Peace being the choice unless you use Proclamation or Return to Ranks. These are good against Dredge, Reanimator decks, as well as Snapcaster and Tarmogoyf decks. 2 of these at least, maybe more.

Non-creature kill:
Sundering Growth, Oblivion Ring, Disenchant, Celestial Purge, Austere Command, Fracturing Gust

Our deck doesn’t answer Planeswalkers, Enchantments or Artifacts, so we want a way to interact with those. Sundering Growth is popular because it has a free token, Oblivion Ring is popular because it’s cheap and hits anything. Celestial Purge is underrated by many, but hits Liliana of the Veil, Death's Shadow, Grim Lavamancer and other problematic cards for us. You can run a split between these, but try to include three or more.

1 CMC:
Sunlance: The deck often wants more removal, and this white bolt does the trick against a lot of decks. Kills many problematic creatures in the format, but struggles because it's only 3 damage which means (Spellskite can eat it and big creatures just shrug it off.
Mana Tithe: Can be a fun way to mess with decks that are always going to go for a specific spell on a specific turn - such as when BGx to taps out on turn 2 to hit a big creature or when decks go for the turn 1 cantrip - but it's much more of a "gotcha!" than anything else.
Faith's Shield: In many cases, a worse Brave The Elements, but occasionally protects you from damage, too. Pay No Heed and Repel The Abominable are better choices.
Pithing Needle: Activated abilities can be a big problem for us, so this is nice. A card that can blank Scooze, Liliana, Ezuri, Aether Vial and numerous other cards is worth considering. Worse if you run Martyr.
Burrenton Forge-Tender: Useful to counter a bolt or stop an Anger of the Gods or Pyroclasm. If R/x decks are rampant in your meta, this or Kor Firewalker are almost mandatory.
Thoughtseize/Inquisition of Kozilek: If you’re in Black, these are likely our best way to stop a combo deck from getting through us. They can also be a useful way to take a creature that would deal more damage than we need to take.
Extirpate/Surgical Extraction: A fun way to stop a dedicated combo deck, keep Tron off of its mana forever or eliminate every copy of a really terrifying card (Ensnaring Bridge in Lantern Control comes to mind) from an opponent’s deck.
Authority of the Consuls: Very fun to stop decks that go wide or infinite, but probably not necessary unless Splinter Twin gets unbanned. Even then, Ghostly Prison might be the better call.
Pay No Heed: A great way to stop Lightning Storm or Valakut, but doesn't stop Grapeshot in storm.

2 CMC:
Stony Silence: Completely kills Affinity post board, with the added bonus of having application against decks like Lantern Control and Tron. Run 2 in the board.
Repel The Abominable: For one more mana than Pay No Heed, you fog all damage done that turn, no matter where it comes from. The human clause allows us to use this as a one-sided wipe at times, as well. The choice if you want this effect.
Kor Firewalker: Doesn't have the counter effect that Burrenton Forge-Tender does, but has a much better body and benefits our lifegain plan. Burn auto-scoops to this, and it buys you some life if UW or Grixis tries to go to the Snapcaster beat down plan.
Suppression Field: Makes fetches and planeswalkers much worse, stops CoCo's infinite game plan, and has application against tons of the best decks in the format.
Mark of Asylum: Stops removal dead in its tracks, which means many of your opponent’s cards just became dead cards. However, this card doesn't give true protection, so it won't help you get in damage or prevent a straight up kill spell like Maelstrom Pulse or a bounce spell like Cryptic Command the way a Brave The Elements might. Which you choose to run is very meta-dependent.
Runed Halo: A solid anti-combo card that can also protect you from beat sticks you can't handle. Not popular, but can be effective in a combo heavy meta.
Phyrexian Revoker: Pithing Needle that can't hit lands, but can stop mana abilities. The body is helpful but very fragile. Again, your meta determines whether you run this or needle.
Blessed Alliance: Flat out replaces Celestial Flare, which was previously one of our best ways to fight bad matchups like Bogles and Infect. Definitely merits a slot or two in your board and has flex application in so many matchups as Paths 5-6.
Celestial Flare: Hilarious against Bogles, Infect, Affinity, and other decks that look to kill you with one creature. You should make room for one or two in metas that heavily feature those decks.
Spellskite: Expensive, but eats Lightning Bolts and other removal for breakfast. Very strong against unfair decks, as well.
Kataki, War's Wage: The body is nice, but this hoses the same things Stony Silence hoses and Stony Silence is usually the better choice.
Leonin Arbiter: Since a hard lock is usually better, Aven Mindcensor is a slightly better choice. Still, this type of effect is really, really good with Path to Exile and Ghost Quarter.
Grand Abolisher: Mostly unusable, but not bad in very counter-heavy metas. If your meta is UWx heavy, he might be worth exploring (though I don't think I would bring Sisters to a UWx heavy-meta)

3CMC:
Aven Mindcensor: Most decks fetch and some decks need to fetch to win, which makes this card very, very good. It makes our own Path to Exiles and Ghost Quarters even more relevant, as well. Many decks run 1-2, with 3 being a little overboard even though the flying body is super relevant.
Ghostly Prison: Any decks that use anthems or lords will get wider than the life they give us, so this becomes a great hoser for aggro swarm decks like Merfolk, Tokens, Zoo, and even Elves. It’s one of the rare sideboard cards that gets better in multiples, but it's tough to justify as many as you want. 1-2 is fine in the right metas.
Ensnaring Bridge: This was a cute option in Eldrazi Winter, but you probably want Ghostly Prison or Worship instead.
Nevermore: A solid lock card that comes down a little late for most people's liking. Only good in combo-heavy metas.
Sword of Light and Shadow: Gives us a pseudo Proclamation of Rebirth effect and a lifegain trigger on really relevant protections. Worth exploring as a one-of.
Sword of Fire and Ice: Again, really relevant protection with a great ability. If R/x decks dominate your meta, consider this.
Mirran Crusader: This card eats Jund/Junk for breakfast. Only great in multiples, though, and at that point, there are better ways to answer the deck. If you want to use a Sword plan, this guy should come along for the ride, though. (Sword of Fire and Ice with this guy is an instant win if they don't have Path to Exile.)

4CMC:

Leyline of Sanctity: Stops Burn, targeted Discard, and combos that hit us for damage. That's usually enough to merit 1-2 in the board. Obviously, three or four is great to make sure you get it in your opener.
Wrath of God: Tough to justify running a sweeper in a creature-heavy build, but this is sometimes our only option against decks like Goblins or Elves and has application in other matchups. If you're using it to kill a creature you would otherwise chump (Like a Goyf,) you're actually saving yourself a lot of card disadvantage.
Linvala, Keeper of Silence: An option to turn off Elves and CoCo Combo, as well as decks that will feast on our graveyard with Scavenging Ooze.
Worship: Keeping a creature alive is remarkably easy for us, so this becomes a great way to turn the tables when a deck starts getting bigger or wider than you. Obviously, you'll have to kill them eventually, but Pridemate can slowly take out their blockers while you just let damage in because you're keeping other things alive.

You want things that fight Non-creature Bogles, Non-damage based combo, and Control, while still having relevance in other matchups to give us an edge. This pretty much does that in Mono-White:


This set up is a little fragile and you would want to modify things once you saw your meta, but you'll be protected from most things.

***Work in progress***

This sideboarding guide assumes you're using one of the default builds and default sideboard. If you're not using that, assume that the overall plan is still similar and adjust your card selection accordingly.

The Black splash opens us up to Lingering Souls, which is one of the best cards in Modern and really helps out our strategy. A common problem with the mono-w version of the deck is that it doesn't interact with other decks enough, which black can solve through Thoughtseize and Orzhov Charm, as well as other cards. Some builds have even tried to work Dark Confidant into the deck as a way to turn our extra life into cards, but Confidant doesn't play well with cards like Spectral Procession and Archangel of Thune.

The general strategy doubles down on tokens, so it borrows heavily from B/W tokens. This is my current sisters 75, which uses a very light black splash. You could go deeper by main decking the Thoughtseizes and using fetches and shocks:



If Fetches and Shocks are out of your budget, Isolated Chapel and Caves of Koilos work just fine. Black also opens us up to sideboard cards like Castigate and Extirpate, which are really good against some of worst match ups (Extirpating a Tron land is an experience you have to have to understand.) 6 black mana producers is more than enough for the Lingering Souls splash.

There's also probably a B/W Sisters build that exploits Blood Artist and Zulaport Cutthroat, but no one has found it, yet. Happy Brewing!

Green has its very own one-drop sister in the form of Essence Warden, as well as card advantage spells like Collected Company, Chord of Calling and Kitchen Finks. The deck can also use cards like Eternal Witness to generate serious value (bringing back a Pridemate or Path from the grave). Many G/W Sisters decks forgo the token plan altogether and look to just curve into really efficient spells that also happen to gain life or do something else that benefits the sisters plan. You can also insert an infinite combo in the form of Spike Feeder + Archangel of Thune.

An example of what G/W sisters looks like is as follows:



Sideboard options like Choke and Dromoka's Command can be nightmares for some matchups where we need help. Green has a fair share of utility lands like Gavony Township, Horizon Canopy and Stirring Wildwood that might interest you, as well.

July 27: 5-0 Modern League (Rvng)
Top 4 SCG Regionals (Light red Splash for Blood Moon out of the side.)

Reid Duke, April 2016
Tom Ross @ GP Charlotte 2015
Rogue Deckbuilder 4-1 PPTQ (April, 2015)
Rogue Deckbuilder 2017 guide
TCC 2014 Deck Tech
Rogue Deckbuilder's 2017 Primer decklists
Did You Know: Soul Sisters

October 24, 2017: Cleanup, new sideboard cards, updated match reports for a shifted meta.
April 14, 2017: Cleanup and new match reports, including Lantern and Death's Shadow, added videos and links
January 1, 2017: Updated matchups to add Dredge, Spirits and other new decks as well as performed cleanup.
August 14, 2016: Updated matchups to add for newer builds, began Sideboarding Guide, began Appendix.
January 16, 2016: Updated primer to reflect Summer Bloom and Splinter Twin bannings.
January 25, 2016: Updated match ups to include B/x Eldrazi.
January 31, 2016: Added a second stock list, for people who want to use Martyr.
February 23, 2016: Added a few decks to the match up report, as well as more cards in the card choices section (mostly B/W cards for the black splash.)