Shirei, Shizo's Caretaker

Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei, Shizo's Caretaker is still on the battlefield.

Apprentice Necromancer

{B}, {T}, Sacrifice Apprentice Necromancer: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Acolyte of Xathrid

Apocalypse Demon

Flying
Apocalypse Demon's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, tap Apocalypse Demon unless you sacrifice another creature.

Akroan Horse

Defender
When Akroan Horse enters, an opponent gains control of it.
At the beginning of your upkeep, each opponent creates a 1/1 white Soldier creature token.

Adaptive Shimmerer

Flash
Adaptive Shimmerer enters with three +1/+1 counters on it.

Abyssal Hunter

{B}, {T}: Tap target creature. Abyssal Hunter deals damage equal to Abyssal Hunter's power to that creature.

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature of their choice.

Amaranthine Wall

Defender
{2}: Amaranthine Wall gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Aether Poisoner

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Aether Poisoner enters, you get {E}{E} (two energy counters).
Whenever Aether Poisoner attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.