Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Vigilance
: Put a +1/+1 counter on this creature.

Trample
Whenever one or more cards leave your graveyard, put a +1/+1 counter on this creature.
When this creature dies, you gain life equal to its power.

This creature enters with X +1/+1 counters on it.
Coven — At the beginning of your end step, if you control three or more creatures with different powers, put a +1/+1 counter on target creature you control.

When this creature enters, create a Blood token. (It's an artifact with ", , Discard a card, Sacrifice this token: Draw a card.")
, Sacrifice this creature: Target creature gets -X/-X until end of turn, where X is twice the number of Blood tokens you control. Activate only as a sorcery.

Up to two target creatures can't block this turn.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

When this creature enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature.

Exile target nonlegendary creature, then return it to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on it. Otherwise, tap it.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Enchant creature
Enchanted creature has "Whenever a creature you control enters, this creature gets +1/+1 until end of turn."
When this Aura enters, create a 1/1 white Spirit creature token with flying.

Reach
At the beginning of your upkeep, mill a card. (Put the top card of your library into your graveyard.)
, , Sacrifice this creature: Create a 1/1 green Insect creature token for each creature card in your graveyard. Activate only as a sorcery.

First strike
Noncreature spells cost more to cast.

Whenever another creature you control dies, put a +1/+1 counter on this creature.

: This creature deals 2 damage to you. Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.
When you play a card exiled with this creature, transform this creature.

Tap three untapped creatures you control: Each opponent loses 1 life.

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, each opponent exiles a card from their hand.

Whenever another Human you control enters, this creature gets +1/+1 until end of turn.

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
When this creature dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

Flying
This creature can't block.

Enchant creature
When this Aura enters, mill two cards. (Put the top two cards of your library into your graveyard.)
Enchanted creature gets -X/-0, where X is the number of cards in your graveyard.

Target player loses 2 life and you gain 2 life. Create two Blood tokens. (They're artifacts with ", , Discard a card, Sacrifice this token: Draw a card.")

Destroy target creature with flying.

Look at the top two cards of target opponent's library. Exile one of them face down and put the other on the bottom of that library. You may play the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.
Flashback

, : Add one mana of any color.
, : Transform this artifact.

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Whenever this creature or another creature you control dies, you gain 1 life.
At the beginning of your end step, if you gained 3 or more life this turn, transform this creature.

Target creature gains deathtouch until end of turn.
Draw a card.

Return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains "If this creature would die, exile it instead."
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

When this creature enters, mill two cards.
Whenever you cast a spell from your graveyard, tap target creature you don't control.
Disturb (You may cast this card from your graveyard transformed for its disturb cost.)

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, destroy target planeswalker.
At the beginning of your upkeep, this creature deals 1 damage to you.

At the beginning of your end step, if you gained life this turn, create a Blood token. (It's an artifact with ", , Discard a card, Sacrifice this token: Draw a card.")
Sacrifice two Blood tokens: Transform this creature. Activate only as a sorcery.

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Exploit (When this creature enters, you may sacrifice a creature.)
Whenever a creature you control exploits a nontoken creature, create a 2/2 black Zombie creature token.

Create X 2/2 black Zombie creature tokens with decayed, where X is half the number of creature cards in your graveyard, rounded up. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Whenever this creature attacks, it deals 1 damage to defending player.

Coven — Choose target creature you control and target creature you don't control. If you control three or more creatures with different powers, put a +1/+1 counter on the chosen creature you control. Then the chosen creatures fight each other. (Each deals damage equal to its power to the other.)

Put a +1/+1 counter on up to one target creature you control. Tap up to one target creature you don't control, and that creature doesn't untap during its controller's next untap step.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)