2B
Creature - Vampire (Class)
Reverse Vampire enters the battlefield with three +1/+1 counters.
When Reverse Vampire deals combat damage to a player, remove a +1/+1 counter from Reverse Vampire.
1/1
Whenever equipped creature attacks, the defending player must share a fact about themselves. If they don't, equipped creature gets an additional +1/+1 until end of turn.
I tried phrasing it as "ask the defending player a question", but that seems like it could get awkward (questions designed so that the opponent doesn't answer).
Liliana's Sock Puppet
(Image: Liliana with a Griselbrand sock puppet and a sad-looking Jace playing a game of Magic.)
1
Artifact
You make all Third Party decisions for both players.
I'm sorry, Jace, but Grizzy says that penguins can't fly. That would be a flavor fail, and nobody wants a flavor fail.
Flavor Fail
W
Enchantment - Aura
If enchanted creature is white, it gains +2/+2 and haste.
If enchanted creature is green, it gains +2/+2 and flying.
If enchanted creature is blue, it gains +2/+2 and trample.
If enchanted creature is black, it gains "at the beginning of your upkeep, you lose one life and each opponent gains one life."
If enchanted creature is red, it gains defender.
Very Tall Wall
3W
Creature - Wall
Reach
Defender
0/99
It was big -- no, bigger than that! It was... never mind, this isn't a very interesting story.
Draw Smoother
1U
Enchantment
Whenever you cast a spell, scry 1.
Sacrifice Draw Smoother: Reveal the bottom three cards of your library. If all of them are lands, draw three cards. Your opponent also draws a card, for being such a good sport.
LSV's Key
3
Artifact
T: Add (1) to your mana pool
2, T: Draw a card, then discard a card
6, T: Draw a card
Generating mana is important. So is drawing cards. Playing spells that do something? Secondary.
-- Luis Scott-Vargas, Planeswalker
Fair Creature
Creature - Beast
3G
If you are playing Standard, Fair Creature costs (1) less to cast and has trample.
If you are playing Modern, Fair Creature costs (2) less to cast.
If you are playing Legacy, Fair Creature costs (3) less to cast and gains "when Fair Creature enters the battlefield, you lose four life".
4/4
Only Morph In The Set
Creature - Platypus
4G
Morph 2G
Islandwalk
4/4
Surprise!
As an addendum to this last one, I think that "Platypus" could be a good creature type for the set's "theme" (a la chickens or donkeys).
Collect 'em all!
2UU - Sorcery
Kicker 5
Search your deck for a card that shares a cycle as target permanent you control and put it into play. If the kicker cost was paid, search for the rest of the cycle instead.
Eratta: If a card is part of multiple cycles you may only search for one of those cycles.
As for "fair creature" add "If you are playing vintage, Fair Creature costs G less and gains haste."
Flavor flair need to have "Enchant a mono-colored creature" W for +6/+6 flying trample haste is completely broken.
Icebreaker, restrict it to a yes or no question. If the attacker can answer correctly it gets the bonus.
Reverse Thraben Inspector
Creature - Human Solider
When Reverse Thraben Inspector enters the battlefield, discard a card unless you pay (2).
2/3
Reverse Elf
Creature - Elf Warrior
G: Untap Reverse Elf.
2/2
Reverse Vampire
Creature - Vampire (Class)
Reverse Vampire enters the battlefield with three +1/+1 counters.
When Reverse Vampire deals combat damage to a player, remove a +1/+1 counter from Reverse Vampire.
1/1
Not great specific ideas, but I like the concept.
Also:
Icebreaker
2
Artifact - Equipment
Equip (2)
Equipped creature gets +2/+1
Whenever equipped creature attacks, the defending player must share a fact about themselves. If they don't, equipped creature gets an additional +1/+1 until end of turn.
Liliana's Sock Puppet
1
Artifact
You make all Third Party decisions for both players.
I'm sorry, Jace, but Grizzy says that penguins can't fly. That would be a flavor fail, and nobody wants a flavor fail.
Flavor Fail
Enchantment - Aura
If enchanted creature is white, it gains +2/+2 and haste.
If enchanted creature is green, it gains +2/+2 and flying.
If enchanted creature is blue, it gains +2/+2 and trample.
If enchanted creature is black, it gains "at the beginning of your upkeep, you lose one life and each opponent gains one life."
If enchanted creature is red, it gains defender.
Very Tall Wall
Creature - Wall
Reach
Defender
0/99
It was big -- no, bigger than that! It was... never mind, this isn't a very interesting story.
Draw Smoother
Enchantment
Whenever you cast a spell, scry 1.
Sacrifice Draw Smoother: Reveal the bottom three cards of your library. If all of them are lands, draw three cards. Your opponent also draws a card, for being such a good sport.
LSV's Key
Artifact
T: Add (1) to your mana pool
2, T: Draw a card, then discard a card
6, T: Draw a card
Generating mana is important. So is drawing cards. Playing spells that do something? Secondary.
-- Luis Scott-Vargas, Planeswalker
Fair Creature
3G
If you are playing Standard, Fair Creature costs (1) less to cast and has trample.
If you are playing Modern, Fair Creature costs (2) less to cast.
If you are playing Legacy, Fair Creature costs (3) less to cast and gains "when Fair Creature enters the battlefield, you lose four life".
4/4
Only Morph In The Set
4G
Morph 2G
Islandwalk
4/4
Surprise!
As an addendum to this last one, I think that "Platypus" could be a good creature type for the set's "theme" (a la chickens or donkeys).
2UU - Sorcery
Kicker 5
Search your deck for a card that shares a cycle as target permanent you control and put it into play. If the kicker cost was paid, search for the rest of the cycle instead.
Eratta: If a card is part of multiple cycles you may only search for one of those cycles.
As for "fair creature" add "If you are playing vintage, Fair Creature costs G less and gains haste."
Flavor flair need to have "Enchant a mono-colored creature" W for +6/+6 flying trample haste is completely broken.
Icebreaker, restrict it to a yes or no question. If the attacker can answer correctly it gets the bonus.