You are certainly not required to keep your hand (partially) revealed, but there's no penalty for doing so if you choose, as long as you keep your hand clearly distinct from your cards on the battlefield. If your opponent intends to take notes about the contents of your hand, though, you can save him the trouble and both of you the time. I see it a lot in playtesting but not so much in tournaments, myself.
16 creatures seems a little light given that you're also running 16 spells that are useless if you don't have a creature to target. Some options to consider:
I was under the impression that Banishing Light can't be used in an endless combo? Can someone explain the combo better?
Banishing Light can be used for an unbounded combo as described in the original post. What they changed with that card compared to Oblivion Ring is that you can't remove the enchantment while its ability is on the stack in order to permanently remove the target. If Banishing Light isn't on the battlefield when its ability resolves, the target will not be exiled at all.
That's not really true. Red is allowed to generate card advantage (more than white), and looting has made its card selection better too. If what MaRo says is true and "Chandraw" becomes a more common ability in red, it doesn't seem all that out of color.
My argument isn't that the effect isn't red. It's that it's out of red at that cost and power level. I'm not MaRo though, so YMMV, I guess.
Chandra's GambitR
Instant
Exile the top three cards of your library. You may play one of those cards this turn. "You have until the flame is an ember. Go."
IIW: Charms
No rarity. I guess there's a little bit of tension here -- choosing one of the cards means you can't play the others. This is probably too good for red at this cost, though.
Jace's GambitU
Instant (U)
Exile the top three cards of your library. You may play one of those cards this turn. "Wait, I'll just be impulsive."
Is that better?
It's closer to fitting in blue, yes. The issue is not really power level per se, but color pie. That effect is fine on a red card, but red's card advantage and card selection are among the worst.
Chandra's GambitR
Instant
Exile the top three cards of your library. You may play one of those cards this turn. "You have until the flame is an ember. Go."
IIW: Charms
No rarity. I guess there's a little bit of tension here -- choosing one of the cards means you can't play the others. This is probably too good for red at this cost, though.
Grafted Bloodsword3
Artifact — Equipment [R]
Equipped creature gets +4/+4.
Whenever a creature enters the battlefield under your control, attach Grafted Bloodsword to that creature.
Whenever Grafted Bloodsword becomes unattached from a creature, that creature's controller sacrifices it. "It's not the sword being ripped from your arm stump that kills you. It's the ichor that pours from your gaping wound that does."
—Azax-Azog, the Demon Thane
IIW: White as the hypocrite, blue as the desperate, black as the hero, red as the architect, or green as the tyrant
A good design, but the tension in this card seems like it won't come into play all that often, at least in constructed. Play a cheap evasive and/or resilient guy, beat down with it until your opponent finds an answer, rinse, repeat.
Fortbreaker Baloth2G
Creature — Beast (R)
Trample
At the beginning of your end step, if Fortbreaker Baloth didn't attack this turn, put a +1/+1 counter on it. Nothing stands in nature's way for long.
1/1
IIW: Big ability costs on tiny things.
This could be uncommon or a little cheaper or larger to start, but I like the design. "Attack now or wait until it gets bigger" is an interesting trade-off.
Torpor Powder2
Artifact - Equipment (U)
Equipped creature has vigilance and "t, Unattach Torpor Powder: Tap target creature."
Equip 2
IIW: Take something distinctly nonblack and make a black variant of it
I don't really see any tension here except maybe the decision between tapping an attacker and leaving the equipped creature untapped to block. Why does "torpor powder" give a creature vigilance?
Oathbound Praetorian1WB
Creature - Skeleton Knight (U) 1W: Oathbound Praetorian gains first strike and vigilance until end of turn. 1B: Regenerate Oathbound Praetorian and it gains lifelink until end of turn. The Praetorian Knights were once the mightiest fighting force in Galgallone. Now, they serve under the very force that emptied the city.
2/2
Galgallone, Cleansed and Lifeless
Legendary Land (R) T: Add one mana of any color to your mana pool for each card that left a graveyard this turn. Spend this mana only to cast spells from your graveyard or to activate abilities of cards in your graveyard. “What I never could figure out is why the angels are still here. They killed all the sinners! Why do they need to drive us away?”
-Kalemi, historian
IIW: Disney villains or Enchantment creatures that are riffs of other enchantments (bonus points for capitalizing on being a creature)
There isn't really much tension here. You can get more mana out of it if you use your other lands to unearth and flashback your stuff first, but the decision ultimately comes down to "here's what i want to cast from my graveyard this turn; can I do it or not?"
Embers of Aenum2R Legendary Enchantment M
At the beginning of your upkeep, put a flame counter on ~. Then ~ deals X damage to each player when X is the number of flame counters on ~.
If ~ would leave the battlefield, exile it, then return it onto the battlefield at the beginning of the next end step.
Collective Consciousness2UU Sorcery U
Each player draws a card, then draw a card for each card drawn this way.
Revengeance3RR Enchantment R
Whenever a red source you control deals damage to an opponent, exile the top card of your library. You may play it until the end of your turn.
Not really seeing much tension in any of these. Collective consciousness has a little bit of a drawback and ties up your mana a bit, but the decision isn't really interesting.
Embers of Aenum2R Legendary Enchantment M
At the beginning of your upkeep, put a flame counter on ~. Then deal X damage to each player when X is the number of flame counters on ~.
If ~ would leave the battlefield, remove all flame counters from it instead.
Collective Consciousness2UU Sorcery U
Each player draws a card, then draw a card for each card drawn this way.
Riff:
Tempt with Knowledge1U
Sorcery {U} Tempting offer — Draw a card. Each opponent may draw a card. For each opponent who does, draw a card.
IIW: Better outside of Standard.
This card is more interesting than Collective Consciousness. Pretty similar in concept to Trade Secrets but executed more cleanly. This could easily cost one mana since without an opponent's consent it's just worse than Peek.
Alpha Imperiosaur2GG
Creature - Lizard
Pack 2/2 (Whenever this attacks, you may put a +1/+1 counter on it. If you don't, remove all +1/+1 counters from it, and put that many 2/2 green Lizard creature tokens onto the battlefield, tapped and attacking.)
3/3
IIW: until
No rarity, but pretty good design (though I agree with AA's comment). The tension here is not too bad -- let the creature keep growing or throw some more attackers out there.
Brutalize1B
Instant (C)
Put a -1/-1 counter on target creature. Tap that creature. The simplest route to victory is to ensure that no one else competes.
An alternate universe Theros where -1/-1 counters are a thing? Reference.
Scaredypants2
Artifact {U}
When equipped creature leaves the battlefield, if it didn't die, it deals damage equal to its power to target creature or player.
Equip 0
Whenever Zibble, Planar Prankster attacks, choose a creature defending player controls at random. It blocks Zibble. (Even if that creature can't legally block, it does anyway.)
Equipment and Auras can't be attached to permanents.
IIW: Offend me
Punniness:
This shouldn't be an uncommon and shouldn't be black. White, red, and green get equipment and aura hating, generally. A narrow hoser like this is better fit for a rare slot.
Hard Cell3
Artifact {U}
Indestructible 3, T: Exchange control of Hard Cell and target nonland permanent unless that permanent's controller pays 5 life.
IIW: A new mechanic for Journey into Nyx.
Punniness:
I get that it's a "hard sell" but I don't get how this artifact that exchanges for other permanents represents a "cell" in any definition of the word. Mechanically it seems fine, although I'd probably make it rare rather than uncommon. I suppose that there's Avarice Totem at uncommon for comparison, but this card is considerably more complex.
All Right NowB
Instant (C)
Target creature gets -X/-X until end of turn, where X is half that creature's power, rounded down. There wasn't much left of him.
Iiw gangsters
Punniness:
It took me a few reads of this one to get the pun, but I like it. No issues with the design -- it won't kill too much outright, but it can work as a cheap combat trick.
Mana Sink3
Artifact (U) XXR,T: ~ deals X damage to target creature or player. XXU,T: Tap X target nonland permanents. Produces pristine T water.
Not so much a pun as a double entendre, but whatever.
IIW: Charms OR 2 CMC black creature commons.
Punniness:
I like that it is a mana sink in both senses of the phrase. Colorless artifacts that do nothing without colored mana are frowned upon, but it works for the sake of the joke.
Hydra-ulicsXG
Creature - Hydra (R)
Hydra-ulics enters the battlefield with X +1/+1 counters on it. 1G: Hydra-ulics gains reach until end of turn. 2G: Hydra-ulics can't be blocked by creatures with flying this turn.
0/0
IIW: Aristocrats/cannibals
Punniness:
The mechanics are a perfect fit for the name. I wish there were a way to make the two abilities mutually exclusive, but I don't really see any elegant way to do so.
Custom Official3(G/W)
Sorcery [U]
If G was spent to play Custom Official, put a 3/3 green Centaur creature token onto the battlefield. If W was spent to cast Custom Official, put a +1/+1 counter on each creature token you control. "It's customary to have a custom guard these days."
IIW: Make me cringe
Punniness:
The mechanics don't fit the name very well, in my opinion. My interpretation of "Custom Official" would be some sort of blue and/or white Primal Clay analogue with the creature type Shapeshifter Advisor.
Put a -1/-1 counter on target creature. If that creature already had a -1/-1 counter on it, put an additional two -1/-1 counters on it.
IIW: Songs I like
Punniness:
I had to do some research to figure out what the pun was, and it only works in the context of AA's card. I would word it a little differently, but it seems balanced enough.
Snow Place Like Home
Snow Land (R) t: Add to your mana pool one mana of any type that a snow land you control could produce.
IIW: lands
Punniness:
Snow Reflecting Pool seems fine. The drawback of only being able to reflect snow lands is offset by the (situational) advantage of being a snow permanent.
Mock Sapphire0
Artifact (M) T, target opponent gains control of Mock Sapphire: Add one mana of any color other than blue to your mana pool. "No, I swear it's real, I just don't want to play blue anymore and am happy to trade down."
IIW: Aristocrats/cannibals
Punniness:
Costs can't target. The flavor text is a nice touch. A strictly worse Lotus Petal at mythic might be printable.
Bad puns? Well clearly my "clever" ophanim naming scheme need not apply!
WetworksXXBB
Sorcery (R)
Wetworks costs 1 less for each Island you control.
Destory X target creatures. Water soothes a guilty conscience. Blood soothes a bored conscience.
IIW: Disney villains or Enchantment creatures that are riffs of other enchantments (bonus points for capitalizing on being a creature)
Punniness:
I get it I guess but it just doesn't tickle my funny bone. Probably printable at this cost and rarity.
Eidolon of the Great Revel does not target the player it damages, so Leyline of Sanctity will not have any effect on it.
Borderland Marauder
Firedrinker Satyr
Foundry Street Denizen
Frenzied Goblin
Goblin Rabblemaster
Mogis's Warhound
Nyxborn Rollicker
Valley Dasher
War-Name Aspirant
Banishing Light can be used for an unbounded combo as described in the original post. What they changed with that card compared to Oblivion Ring is that you can't remove the enchantment while its ability is on the stack in order to permanently remove the target. If Banishing Light isn't on the battlefield when its ability resolves, the target will not be exiled at all.
My argument isn't that the effect isn't red. It's that it's out of red at that cost and power level. I'm not MaRo though, so YMMV, I guess.
It's closer to fitting in blue, yes. The issue is not really power level per se, but color pie. That effect is fine on a red card, but red's card advantage and card selection are among the worst.
No rarity. I guess there's a little bit of tension here -- choosing one of the cards means you can't play the others. This is probably too good for red at this cost, though.
A good design, but the tension in this card seems like it won't come into play all that often, at least in constructed. Play a cheap evasive and/or resilient guy, beat down with it until your opponent finds an answer, rinse, repeat.
This could be uncommon or a little cheaper or larger to start, but I like the design. "Attack now or wait until it gets bigger" is an interesting trade-off.
I don't really see any tension here except maybe the decision between tapping an attacker and leaving the equipped creature untapped to block. Why does "torpor powder" give a creature vigilance?
There isn't really much tension here. You can get more mana out of it if you use your other lands to unearth and flashback your stuff first, but the decision ultimately comes down to "here's what i want to cast from my graveyard this turn; can I do it or not?"
Not really seeing much tension in any of these. Collective consciousness has a little bit of a drawback and ties up your mana a bit, but the decision isn't really interesting.
This card is more interesting than Collective Consciousness. Pretty similar in concept to Trade Secrets but executed more cleanly. This could easily cost one mana since without an opponent's consent it's just worse than Peek.
No rarity, but pretty good design (though I agree with AA's comment). The tension here is not too bad -- let the creature keep growing or throw some more attackers out there.
Next round: Big ability costs on tiny things.
Instant (C)
Put a -1/-1 counter on target creature. Tap that creature.
The simplest route to victory is to ensure that no one else competes.
IIW: Cards with tension.
Pants on Fire 2
Artifact (U)
Equipped creature has haste.
R: Pants on Fire deals 1 damage to equipped creature.
Equip
Enchantress's Robe 2
Artifact - Equipment (U)
Equipped creature gets +1/+1 for each enchantment you control.
Equip
IIW: Cards with tension.
Fixed the wording.
Punniness:
This shouldn't be an uncommon and shouldn't be black. White, red, and green get equipment and aura hating, generally. A narrow hoser like this is better fit for a rare slot.
Punniness:
I get that it's a "hard sell" but I don't get how this artifact that exchanges for other permanents represents a "cell" in any definition of the word. Mechanically it seems fine, although I'd probably make it rare rather than uncommon. I suppose that there's Avarice Totem at uncommon for comparison, but this card is considerably more complex.
Punniness:
It took me a few reads of this one to get the pun, but I like it. No issues with the design -- it won't kill too much outright, but it can work as a cheap combat trick.
Punniness:
I like that it is a mana sink in both senses of the phrase. Colorless artifacts that do nothing without colored mana are frowned upon, but it works for the sake of the joke.
Punniness:
The mechanics are a perfect fit for the name. I wish there were a way to make the two abilities mutually exclusive, but I don't really see any elegant way to do so.
Punniness:
The mechanics don't fit the name very well, in my opinion. My interpretation of "Custom Official" would be some sort of blue and/or white Primal Clay analogue with the creature type Shapeshifter Advisor.
Punniness:
I had to do some research to figure out what the pun was, and it only works in the context of AA's card. I would word it a little differently, but it seems balanced enough.
Punniness:
Snow Reflecting Pool seems fine. The drawback of only being able to reflect snow lands is offset by the (situational) advantage of being a snow permanent.
Punniness:
Costs can't target. The flavor text is a nice touch. A strictly worse Lotus Petal at mythic might be printable.
Punniness:
I get it I guess but it just doesn't tickle my funny bone. Probably printable at this cost and rarity.
Next round: Aristocrats/cannibals.
Challenge errata: double entendres are more than welcome as well.
Creature - Canathid Scout (U)
Whenever ~ becomes blocked, return it to its owner's hand.
4/4
IIW: Bad puns are go.