The card is based after a card named Window from a game called Android:Netrunner, where its effect is largely considered too niche to be useful.
I wanted to see how it could work in MTG, since it does some cool things with cards that put cards on top of your library (like Jace, the Mind Sculptor / Brainstorm) as well as cards that put cards on the bottom of your library (like Peer Through Depths and anything with scry).
If you run the Power Artifact monolith packages, the common mana sinks are draw spells like Braingeyser, Stroke of Genius, Blue Sun's Zenith, or Sphinx's Revelation, or a straight-up kill from something like Exsanguinate or Debt to the Deathless. Overall, this doesn't seem like much of a Zur deck, actually. Unless I missed something, your only targets are the detention sphere and necropotence, and necropotence's delayed payoff means that it can be removed without you actually "going off", and once it gets removed your commander does almost nothing. I think the deck is fine as a whole, but Zur may not be the commander you want unless you grab some more targets. You don't need like 10 to capitalize on zur, but I would have more than 2 or 3.
Unless I'm missing something, when Master of Waves leaves play, the tokens have a toughness of 0 and will leave play as a state-based action, which means you will not net more tokens than you started with.
You're missing something. State-based actions are only checked after Brago's ability resolves, meaning that while the master of waves leaves play, by the time SBAs are checked the master is already back. This is why you can't Corrupt yourself to death: even though you hit 0 life during the resolution of the spell by the time the game checks your life total you're back above 0. More specifically, it matters that Brago's ability is like Restoration Angel, Cloudshift, and Momentary Blink, and not like Mistmeadow Witch or Flickerwisp, which would kill the tokens.
I would look into Invader Parasite, Price of Progress, and Ruby Medallion. I've gotta imagine that Ruby Medallion is probably better in the Mono-Red deck than Fellwar stone since it will regularly provide multiple mana per turn. Also, why Temporal Aperture? It seems like Planar Portal might be a nicer fit, since you don't really have anything to take advantage of the 2 casting cost, and it has a lot of whammies to hit, such as your 38 lands, starstorm, and firecat blitz, not to mention just hitting something with no targets or only contextual use like Vandalblast, Skred, or All is Dust and Blasphemous Act when you don't want to cast them. Stranglehold doesn't even prevent you from searching your own library.
Cards I'm considering
I mentioned that the reanimator package has the benefit of allowing us to play without resources as long as we can keep zur on the table. For this reason, I'm looking at cards like Contamination, Ravages of War, and Armageddon to allow us to actually create that gamestate rather than just be resilient in it. This has the added benefit of playing into the 11 mana rocks in the deck to allow us to operate on little to no land much more effectively.On that note, I'm also looking at Mana Crypt and Mana Vault, if the deck moves towards the Ravages of War plan to further facilitate this artifact mana plan.
I'm also looking at additional tutoring effects, like Vampiric Tutor, Imperial Seal, and Fabricate. In any deck that focuses heavily on putting together combos, as this does, tutoring effects are key to find combo pieces. These would have the strongest implications for our Power Artifact combo, as zur can easily find the enchantment side of it, but the deck could do with extra tutoring for the artifact end of the bargain. I think if additional slots are devoted to tutoring for the monoliths, additional cards like Soothsaying, Scroll Rack, and Stroke of Genius could come in to make use of the more consistent access to infinite mana.
The reanimation package has a little bit of fat that could be trimmed, and could possibly maintain its grinding potential with fewer cards for an overall leaner deck. Additionally, the fact that the deck uses both its graveyard and artifact mana means that we can tutor for neither Stony Silence nor Rest in Peace, so we sacrifice some of the utility Zur's ability has as a hate effect. If you have any feedback or suggestions, let me know! The deck's a blast.
I consider both round 5 cards to be pretty sketchy, but I prefer the WB one.
I don't consider either of them to be that sketchy, given that Essence Drain is a card, and that each of the colors that have been mixed with black in this circumstance share at least half of the effect. In general, thought I would say the W/B one makes more sense to me, as red tends to get efficient lifegain less than white gets creature damage.
Magneticoil enters the battlefield with X charge counters on it.
Whenever equipped creature deals combat damage to a player, you may remove all charge counters from magneticoil and sacrifice it.
If you do, gain control of all artifacts that player controls with converted mana cost less than or equal to the number of counters removed this way.
Equip 1
Galvanic Wargear 3
Artifact - Equipment
Equipped creature gets +X/-X and has trample and haste, where X is its toughness minus 1.
At the beginning of the end step, sacrifice equipped creature.
Whenever Galvanic wargear becomes unattached from a creature, sacrifice that creature.
I feel like there's a bias against creating extremely powerful cards in this forum, even though wizards has made the same kind of decisions that amateur designers make. I think that It's okay to design cards in the same league as Yawgmoth's Will and Ancestral Recall as long as you acknowledge what they're going to be used for. I mean, Richard Garfield, who has undoubtedly read every dissertation under the sun on Nash Equilibriums and game design still okayed Time Walk.
On the subject of this card specifically, maybe something like Sanguine Pact or Blood Pact? I have no problems with the design of this card, though it's undoubtedly extremely powerful. I feel like the creature sacrifice part is a concession to power level that interferes with the design of that card, honestly, and would be much more satisfied to see this card as a vintage and cube only card with the original printing.
Here are a few cards I came up with recently. If you have any opinions on them or wording suggestions I'd be happy to hear!
Freya Fireheart 3GGG
Legendary Creature - Giant Warrior
Whenever another creature enters the battlefield, Freya Fireheart fights that creature.
Whenever a creature dealt damage by Freya Fireheart this turn dies, put a +1/+1 counter on Freya Fireheart.
6/5
Fleshfly Swarm 1BB
Creature - Insect
Whenever another creature dies, if Fleshfly Swarm is in your graveyard, exile that creature. If you do, return Fleshfly swarm from your graveyard to play.
1/1
Pyromania 2RR
Enchatment
You can't cast nonred spells.
Red spells you cast cost R less to cast.
Whenever a red source you control would deal damage to a creature or player, it deals that much damage plus 1 instead.
Have you guys claiming that they'll only count for one side ever played with the chroma mechanic? It's the same idea. Devotion and chroma track the exact same portion of the card, and conveniently enough for comparison, chroma also existed at the same time as cards with hybrid mana costs, and they counted hybrid cards in determining the number of both symbols in mana costs of permanents.
Furthermore, can you imagine how complicated it would be if devotion was determined by some arbitrary allocation of the symbols on the permanents? When would you decide how many boros reckoner symbols you wanted to be red and how many you wanted to be white? How would you indicate it? Wouldn't this add unnecessary delays to games where devotion is irrelevant? Why have players never had to make this decision before when determining whether boros reckoner increased devotion to both red and white or some mix of 3 symbols?
The hybrid cards will almost certainly count for double devotion for the cards which care about devotion to both of its colors, and R&D has most likely taken into account that the R/W and the U/B gods have cards that turn them into creatures immediately.
The immediate comparison is Chaos Charm, and this card is certainly more powerful than that. I don't think that this card is busted or unprintable, but I do think that it could stand to overlap with existing charms a bit less.
So the first mode is crush, which as smelt shows is probably not a very powerful card and functional upgrades to it are pretty reasonable. This is a very good "charm" kind of effect.
The second mode is burst of speed, which I would tend to avoid on this charm. In terms of absolute power it's not quite a gamebreaker, but when both Chaos Charm and Fever Charm already put haste on 1-mana charms and made it single-target. I would replace this with another effect.
The third mode seems fine, though for what it's worth most charms do not offer you much versatility in terms of your targets and it's common to have separate effects which target creatures and players. With only one damage coming off of this spell I would tend to expect this to be mostly directed at creatures (barring chandra's phoenix and the like). I would consider either messing with the targeting conditions and numbers for this card, (in the way that Fever Charm's damage effect is narrow and powerful compared to Chaos Charm) or changing the effect.
Storm of Herons: Common white removal is usually not quite that good. See Iona's Judgment. At instant and able to be used to gain life in a pinch, this card's much more versatile than that despite its drawback.
Priestmount gains too much life in my opinion. The Refuges saw some play, Nomad Stadium has even seen play, and I think that this is much, much better than those. Consider that unless an opponent puts out 4 damage a turn, they're unable to race your LAND, and at 4 they only break even. Generally if lands are going to gain you life, it's either 1-shot like the refuges or Kabira Crossroads, require you to sacrifice permanents like Diamond Valley, Miren, the Moaning Well, or Starlit Sanctum, and in the white-blue colors specifically, the most comparable card is Prahv, Spires of Order, which is a bit more flexible but I would say also much less powerful than this card.
Cloudbreaker's very cool. I might go with exile another target creature and leaves play over dies, but that's just me being a johnny. The current version is totally fine.
The planeswalker is pretty neat, but I have a few problems with the abilities.
+1: The exile seems a bit tacked on here, and Venser, the Sojourner already had her exact mana cost and flickered (even if it was only your own permanents). I assume that the ability is supposed to protect Ursula by giving creatures summoning sickness, but it's kind of unintuitive to have the cards come back during the opponent's upkeep and have summoning sickness considering that turn considering that the only time before it when players have priority is the end step, when most cards of this kind return permanents.
-4: Seems fine
-8: Gotta say, this actually feels a little weak. It gains you a boatload of life (maybe), clears tokens and counters from opponents' permanents, and keeps your opponents from doing anything that turn, but those are generally minor effects. And it only draws you one card, same as the first skill.
What about something like: Exile another target nonland permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step. You gain 3 life. You may repeat this process any number of times.
That allows you to avoid triggering your opponents' enters the battlefield effects, keeps the exiling in the traditional white-blue realm of nonland permanents, and scales the lifegain up to match the fact that you don't gain a life from each land, lets you hit your nonland permanents if you like, and draws a bunch of cards.
I would suggest perhaps some other sort of protection. Maybe detain? I'm just saying that considering she has the same cost and colors as venser it might be wise to minimize the overlap between their skills, and since you can't plan on your opponent's deck, I can see her first skill being used in a very similar way to venser's.
@mondu:
So first the mad oracle stuff.
There are no rules issues with mad oracle. See Epic Experiment. X is always 0, and cost reduction doesn't matter because it doesn't change the mana cost of the cards, so you can have as many Goblin Electromancers as you want in play, but you still have to pay 1R (or more for the first version) if your top card is Searing Spear. It doesn't ask you to cast the card, it just asks if the card's mana cost (which is fixed) could be paid using the mana used for X. For example, if someone casts Ignite Memories on you, you don't take less damage from having Helm of Awakening or more from Sphere of Resistance.
Furthermore the card you posted is fundamentally different. It has no timing restrictions, where as mad oracle forces you to cast the card immediately or lose it forever, it filters your mana to allow you to cast cards of any color (which seems like a bad idea), which makes it easy to cast the card, as opposed to requiring you to guess the specific mana cost of the card on top of your library.
As far as the Lake of Tar, you raise a good point about the creatures losing their toughness. I think the card would still work more or less if the cards filled the pit according to converted mana cost.
Avatar of Sorrow 1UB
Creature - Avatar
Flying
Whenever a creature dies, you may tap target creature. If you do, it doesn't untap during its controller's untap step for as long as you control Avatar of Sorrow.
I fell to the ground weeping in horror; I could have mourned my entire life. As I felt its presence draw away from me, I felt an emptiness at the loss of something for which I have no name.
3/1
Lake of Tar XBB
Enchantment
Lake of Tar enters the battlefield with X tar counters on it.
Whenever a creature without flying attacks, it gets -1/-1 for each tar counter on Lake of Tar until end of turn.
Whenever a creature dies, remove tar counters from Lake of Tar equal to that creature's toughness.
San Simon's tar fields rendered it impenetrable until the mound of forgotten invaders stood so high that their successors crossed on a bridge of corpses.
Not quite sure how to word the last line of Lake of Tar.
And here are a couple of fixed (hopefully) cards which I came up with in the past, but which were off for power/flavor reasons.
Aya the Turbulent 1RR
Legendary Creature - Human Wizard
Red instant and Sorcery cards you own have madness. Their madness cost is equal to their mana cost.
If you would discard a card at random, instead discard a card. T: Target player discards a card at random, then draws a card.
0/2
This last card was originally black, is being changed to red for pie concerns, and I was wondering about two different iterations of the card, depending on how powerful its ability is.
Mad Oracle 1R
Creature - Human Cleric X, T: Reveal the top card of your library. If its mana cost could be paid using only mana spent to pay X, you may cast it without paying its mana cost. If you don't, exile it.
2/1
Mad Oracle 1R
Creature - Human Cleric X, T: Reveal the top card of your library. If its mana cost is equal to X, you may cast it without paying its mana cost. If you don't, exile it.
2/1
Rain of Fire 3RR
Sorcery
Rain of fire deals 20 damage divided evenly, rounded up between all creatures and players.
So obvious things first. First, this card deals a bunch of damage, and has the potential to nug your opponent for a bunch, but only on a completely empty board, less in multiplayer, and it will never deal more damage to them than it does to you. The division of damage keeps aggressive decks from abusing this as a double lava axe, and in general gives the card potential to be played with and around.
Second, it has the potential to deal a good amount of damage to creatures, and is different at different points.
when there are 20 or more total creatures and players, it's rain of embers.
When the number of targets is between 20 and 10, it's steam blast.
When there are 9-7 targets, it's Sulfurous Blast (since it can only be cast during a main phase normally).
From 6-5 it's 4 damage per target, at 4 it's 5 damage per target, and at 3 it's 7 per target.
Mad Oracle 1B
Creature - Human Cleric X,T:Reveal the top card of your library. If its mana cost could be paid using only mana used to pay X, you may cast it without paying its mana cost. If you don't, exile it.
2/1
The card is based after a card named Window from a game called Android:Netrunner, where its effect is largely considered too niche to be useful.
I wanted to see how it could work in MTG, since it does some cool things with cards that put cards on top of your library (like Jace, the Mind Sculptor / Brainstorm) as well as cards that put cards on the bottom of your library (like Peer Through Depths and anything with scry).
You're missing something. State-based actions are only checked after Brago's ability resolves, meaning that while the master of waves leaves play, by the time SBAs are checked the master is already back. This is why you can't Corrupt yourself to death: even though you hit 0 life during the resolution of the spell by the time the game checks your life total you're back above 0. More specifically, it matters that Brago's ability is like Restoration Angel, Cloudshift, and Momentary Blink, and not like Mistmeadow Witch or Flickerwisp, which would kill the tokens.
1x Zur the Enchanter
Land (37)
1x Adarkar Wastes
1x Arcane Sanctum
1x Azorius Chancery
1x Caves of Koilos
1x Command Tower
1x Dimir Aqueduct
1x Drowned Catacomb
1x Fetid Heath
1x Flooded Strand
1x Glacial Fortress
1x Godless Shrine
1x Hall of the Bandit Lord
1x Hallowed Fountain
3x Island
1x Isolated Chapel
1x Marsh Flats
1x Maze of Ith
1x Mystic Gate
1x Nimbus Maze
1x Orzhov Basilica
4x Plains
1x Polluted Delta
1x River of Tears
1x Sunken Ruins
5x Swamp
1x Underground River
1x Urborg, Tomb of Yawgmoth
1x Watery Grave
Planeswalker (1)
1x Liliana of the Veil
1x Academy Rector
1x Ashen Rider
1x Doomed Necromancer
1x Dreamscape Artist
1x Elesh Norn, Grand Cenobite
1x Glen Elendra Archmage
1x Griselbrand
1x Iona, Shield of Emeria
1x Karmic Guide
1x Mikaeus, the Unhallowed
1x Phyrexian Delver
1x Reya Dawnbringer
1x Shriekmaw
1x Silent Sentinel
1x Solemn Simulacrum
1x Sun Titan
Enchantment (12)
1x Animate Dead
1x Attunement
1x Aura of Silence
1x Copy Artifact
1x Copy Enchantment
1x Dance of the Dead
1x Detention Sphere
1x Necromancy
1x Necropotence
1x Oblivion Ring
1x Phyrexian Arena
1x Power Artifact
Artifact (13)
1x Azorius Signet
1x Basalt Monolith
1x Coalition Relic
1x Dimir Signet
1x Fellwar Stone
1x Gilded Lotus
1x Grim Monolith
1x Lightning Greaves
1x Mimic Vat
1x Orzhov Signet
1x Sol Ring
1x Talisman of Dominance
1x Talisman of Progress
1x Austere Command
1x Beseech the Queen
1x Braingeyser
1x Buried Alive
1x Compulsive Research
1x Damnation
1x Demonic Tutor
1x Exsanguinate
1x Living Death
1x Rite of Replication
1x Victimize
1x Wrath of God
Instant (8)
1x Cryptic Command
1x Cyclonic Rift
1x Entomb
1x Fact or Fiction
1x Hinder
1x Lim-Dul's Vault
1x Negate
1x Sphinx's Revelation
The deck plans to use Zur to tutor for various combo pieces or cards that are synergistic with whatever is currently available. Rather than
Some cool features of the deck:
Power Artifact provides a neat infinite mana combo that's easily tutorable with zur. With our 3 X-Spells, Sphinx's Revelation,Braingeyser, and Exsanguinate, we can go for the kill by either exsanguinating everyone, or by drawing into a bunch of mana rocks and exsanguinate, tapping them for sufficient black and exsanguinating everyone. Another fringe benefit to this is that we can cast Beseech the Queen for 6 without using colored mana.
The reanimator package lends itself to long chains of reanimation, thanks to the ability of Sun Titan to reanimate our 3 auras, along with Phyrexian Delver and Karmic Guide/card]. This line of play is less explosive, but provides great value and allows us to operate without cards in hand or mana to cast spells. If we can keep Zur in play, and no player has mana available (perhaps due to Ravages of War, Armageddon, or Cataclysm), we can tutor up a string of cards like Attunement and Necromancy to get one of our big reanimation targets into play, which either have the capability of closing out the game themselves or constitute a secondary engine of card advantage to bring us back into the game.
Cards I'm considering
I mentioned that the reanimator package has the benefit of allowing us to play without resources as long as we can keep zur on the table. For this reason, I'm looking at cards like Contamination, Ravages of War, and Armageddon to allow us to actually create that gamestate rather than just be resilient in it. This has the added benefit of playing into the 11 mana rocks in the deck to allow us to operate on little to no land much more effectively.On that note, I'm also looking at Mana Crypt and Mana Vault, if the deck moves towards the Ravages of War plan to further facilitate this artifact mana plan.
I'm also looking at additional tutoring effects, like Vampiric Tutor, Imperial Seal, and Fabricate. In any deck that focuses heavily on putting together combos, as this does, tutoring effects are key to find combo pieces. These would have the strongest implications for our Power Artifact combo, as zur can easily find the enchantment side of it, but the deck could do with extra tutoring for the artifact end of the bargain. I think if additional slots are devoted to tutoring for the monoliths, additional cards like Soothsaying, Scroll Rack, and Stroke of Genius could come in to make use of the more consistent access to infinite mana.
The reanimation package has a little bit of fat that could be trimmed, and could possibly maintain its grinding potential with fewer cards for an overall leaner deck. Additionally, the fact that the deck uses both its graveyard and artifact mana means that we can tutor for neither Stony Silence nor Rest in Peace, so we sacrifice some of the utility Zur's ability has as a hate effect. If you have any feedback or suggestions, let me know! The deck's a blast.
I don't consider either of them to be that sketchy, given that Essence Drain is a card, and that each of the colors that have been mixed with black in this circumstance share at least half of the effect. In general, thought I would say the W/B one makes more sense to me, as red tends to get efficient lifegain less than white gets creature damage.
Artifact - Equipment
Magneticoil enters the battlefield with X charge counters on it.
Whenever equipped creature deals combat damage to a player, you may remove all charge counters from magneticoil and sacrifice it.
If you do, gain control of all artifacts that player controls with converted mana cost less than or equal to the number of counters removed this way.
Equip 1
Galvanic Wargear 3
Artifact - Equipment
Equipped creature gets +X/-X and has trample and haste, where X is its toughness minus 1.
At the beginning of the end step, sacrifice equipped creature.
Whenever Galvanic wargear becomes unattached from a creature, sacrifice that creature.
Equip 0
On the subject of this card specifically, maybe something like Sanguine Pact or Blood Pact? I have no problems with the design of this card, though it's undoubtedly extremely powerful. I feel like the creature sacrifice part is a concession to power level that interferes with the design of that card, honestly, and would be much more satisfied to see this card as a vintage and cube only card with the original printing.
Freya Fireheart
3GGG
Legendary Creature - Giant Warrior
Whenever another creature enters the battlefield, Freya Fireheart fights that creature.
Whenever a creature dealt damage by Freya Fireheart this turn dies, put a +1/+1 counter on Freya Fireheart.
6/5
Fleshfly Swarm
1BB
Creature - Insect
Whenever another creature dies, if Fleshfly Swarm is in your graveyard, exile that creature. If you do, return Fleshfly swarm from your graveyard to play.
1/1
Pyromania
2RR
Enchatment
You can't cast nonred spells.
Red spells you cast cost R less to cast.
Whenever a red source you control would deal damage to a creature or player, it deals that much damage plus 1 instead.
Furthermore, can you imagine how complicated it would be if devotion was determined by some arbitrary allocation of the symbols on the permanents? When would you decide how many boros reckoner symbols you wanted to be red and how many you wanted to be white? How would you indicate it? Wouldn't this add unnecessary delays to games where devotion is irrelevant? Why have players never had to make this decision before when determining whether boros reckoner increased devotion to both red and white or some mix of 3 symbols?
The hybrid cards will almost certainly count for double devotion for the cards which care about devotion to both of its colors, and R&D has most likely taken into account that the R/W and the U/B gods have cards that turn them into creatures immediately.
So the first mode is crush, which as smelt shows is probably not a very powerful card and functional upgrades to it are pretty reasonable. This is a very good "charm" kind of effect.
The second mode is burst of speed, which I would tend to avoid on this charm. In terms of absolute power it's not quite a gamebreaker, but when both Chaos Charm and Fever Charm already put haste on 1-mana charms and made it single-target. I would replace this with another effect.
The third mode seems fine, though for what it's worth most charms do not offer you much versatility in terms of your targets and it's common to have separate effects which target creatures and players. With only one damage coming off of this spell I would tend to expect this to be mostly directed at creatures (barring chandra's phoenix and the like). I would consider either messing with the targeting conditions and numbers for this card, (in the way that Fever Charm's damage effect is narrow and powerful compared to Chaos Charm) or changing the effect.
Priestmount gains too much life in my opinion. The Refuges saw some play, Nomad Stadium has even seen play, and I think that this is much, much better than those. Consider that unless an opponent puts out 4 damage a turn, they're unable to race your LAND, and at 4 they only break even. Generally if lands are going to gain you life, it's either 1-shot like the refuges or Kabira Crossroads, require you to sacrifice permanents like Diamond Valley, Miren, the Moaning Well, or Starlit Sanctum, and in the white-blue colors specifically, the most comparable card is Prahv, Spires of Order, which is a bit more flexible but I would say also much less powerful than this card.
Cloudbreaker's very cool. I might go with exile another target creature and leaves play over dies, but that's just me being a johnny. The current version is totally fine.
The planeswalker is pretty neat, but I have a few problems with the abilities.
+1: The exile seems a bit tacked on here, and Venser, the Sojourner already had her exact mana cost and flickered (even if it was only your own permanents). I assume that the ability is supposed to protect Ursula by giving creatures summoning sickness, but it's kind of unintuitive to have the cards come back during the opponent's upkeep and have summoning sickness considering that turn considering that the only time before it when players have priority is the end step, when most cards of this kind return permanents.
-4: Seems fine
-8: Gotta say, this actually feels a little weak. It gains you a boatload of life (maybe), clears tokens and counters from opponents' permanents, and keeps your opponents from doing anything that turn, but those are generally minor effects. And it only draws you one card, same as the first skill.
What about something like: Exile another target nonland permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step. You gain 3 life. You may repeat this process any number of times.
That allows you to avoid triggering your opponents' enters the battlefield effects, keeps the exiling in the traditional white-blue realm of nonland permanents, and scales the lifegain up to match the fact that you don't gain a life from each land, lets you hit your nonland permanents if you like, and draws a bunch of cards.
I would suggest perhaps some other sort of protection. Maybe detain? I'm just saying that considering she has the same cost and colors as venser it might be wise to minimize the overlap between their skills, and since you can't plan on your opponent's deck, I can see her first skill being used in a very similar way to venser's.
So first the mad oracle stuff.
There are no rules issues with mad oracle. See Epic Experiment. X is always 0, and cost reduction doesn't matter because it doesn't change the mana cost of the cards, so you can have as many Goblin Electromancers as you want in play, but you still have to pay 1R (or more for the first version) if your top card is Searing Spear. It doesn't ask you to cast the card, it just asks if the card's mana cost (which is fixed) could be paid using the mana used for X. For example, if someone casts Ignite Memories on you, you don't take less damage from having Helm of Awakening or more from Sphere of Resistance.
Furthermore the card you posted is fundamentally different. It has no timing restrictions, where as mad oracle forces you to cast the card immediately or lose it forever, it filters your mana to allow you to cast cards of any color (which seems like a bad idea), which makes it easy to cast the card, as opposed to requiring you to guess the specific mana cost of the card on top of your library.
As far as the Lake of Tar, you raise a good point about the creatures losing their toughness. I think the card would still work more or less if the cards filled the pit according to converted mana cost.
Creature - Avatar
Flying
Whenever a creature dies, you may tap target creature. If you do, it doesn't untap during its controller's untap step for as long as you control Avatar of Sorrow.
I fell to the ground weeping in horror; I could have mourned my entire life. As I felt its presence draw away from me, I felt an emptiness at the loss of something for which I have no name.
3/1
Lake of Tar XBB
Enchantment
Lake of Tar enters the battlefield with X tar counters on it.
Whenever a creature without flying attacks, it gets -1/-1 for each tar counter on Lake of Tar until end of turn.
Whenever a creature dies, remove tar counters from Lake of Tar equal to that creature's toughness.
San Simon's tar fields rendered it impenetrable until the mound of forgotten invaders stood so high that their successors crossed on a bridge of corpses.
Not quite sure how to word the last line of Lake of Tar.
And here are a couple of fixed (hopefully) cards which I came up with in the past, but which were off for power/flavor reasons.
Aya the Turbulent 1RR
Legendary Creature - Human Wizard
Red instant and Sorcery cards you own have madness. Their madness cost is equal to their mana cost.
If you would discard a card at random, instead discard a card.
T: Target player discards a card at random, then draws a card.
0/2
This last card was originally black, is being changed to red for pie concerns, and I was wondering about two different iterations of the card, depending on how powerful its ability is.
Mad Oracle 1R
Creature - Human Cleric
X, T: Reveal the top card of your library. If its mana cost could be paid using only mana spent to pay X, you may cast it without paying its mana cost. If you don't, exile it.
2/1
Mad Oracle 1R
Creature - Human Cleric
X, T: Reveal the top card of your library. If its mana cost is equal to X, you may cast it without paying its mana cost. If you don't, exile it.
2/1
Sorcery
Rain of fire deals 20 damage divided evenly, rounded up between all creatures and players.
So obvious things first. First, this card deals a bunch of damage, and has the potential to nug your opponent for a bunch, but only on a completely empty board, less in multiplayer, and it will never deal more damage to them than it does to you. The division of damage keeps aggressive decks from abusing this as a double lava axe, and in general gives the card potential to be played with and around.
Second, it has the potential to deal a good amount of damage to creatures, and is different at different points.
when there are 20 or more total creatures and players, it's rain of embers.
When the number of targets is between 20 and 10, it's steam blast.
When there are 9-7 targets, it's Sulfurous Blast (since it can only be cast during a main phase normally).
From 6-5 it's 4 damage per target, at 4 it's 5 damage per target, and at 3 it's 7 per target.
Mad Oracle 1B
Creature - Human Cleric
X,T:Reveal the top card of your library. If its mana cost could be paid using only mana used to pay X, you may cast it without paying its mana cost. If you don't, exile it.
2/1