When Abyssal Gatekeeper dies, each player sacrifices a creature.

Sacrifice a creature: Add {C}{C}.

Indestructible

As long as your devotion to white and black is less than seven, Athreos isn't a creature.

Whenever another creature you own dies, return it to your hand unless target opponent pays 3 life.

{T}: Add {W}.

At the beginning of your upkeep, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

When Bastion of Remembrance enters the battlefield, create a 1/1 white Human Soldier creature token.

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Return up to two target creature cards with total mana value 3 or less from your graveyard to the battlefield. Put a deathtouch counter on either of them. Then put a menace counter on either of them.

Vigilance, reach

Whenever Colfenor, the Last Yew or another creature you control dies, return up to one other target creature card with lesser toughness from your graveyard to your hand.

Whenever Cruel Celebrant or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.

Whenever a creature is dealt damage, destroy it. It can't be regenerated.

{T}: Exile target land card from a graveyard. Add one mana of any color.

{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.

{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

Flash

Creatures you control get +2/+2.

Exile target creature. If you don't control a Human, you lose life equal to that creature's toughness.

Fertilid enters the battlefield with two +1/+1 counters on it.

{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.

Destroy all creatures that entered the battlefield this turn.

When Hecatomb enters the battlefield, sacrifice Hecatomb unless you sacrifice four creatures.

Tap an untapped Swamp you control: Hecatomb deals 1 damage to any target.

Creatures you control get +0/+1.

Morph {1}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Mutate {4}{G/W}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Deathtouch, lifelink

Whenever this creature mutates, return any number of target creature cards with total power 10 or less from your graveyard to the battlefield.

You may cast Parapet as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.

Creatures you control get +0/+1.

Whenever Pawn of Ulamog or another nontoken creature you control dies, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Reach (This creature can block creatures with flying.)

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Whenever another creature dies, each opponent loses 1 life.

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control, then sacrifices a third of the lands they control. Round up each time.

{T}, Sacrifice two other creatures: Any number of target players each lose 2 life and sacrifice a creature. You add {B}{B} and draw a card.

Flying

When Reveillark leaves the battlefield, return up to two target creature cards with power 2 or less from your graveyard to the battlefield.

Evoke {5}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

{1}{B}, Exile a card from your graveyard: Screams of the Damned deals 1 damage to each creature and each player.

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

At the beginning of each opponent's upkeep, that player sacrifices a creature.

{T}: Add {B} or {G}.

{T}: Mill two cards.

{T}: Add {C}{C}.

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

When Solemn Simulacrum dies, you may draw a card.

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.

Destroy target creature or planeswalker.

Creatures you control get +1/+1.

{1}{W}{W}, {T}: Destroy target creature that dealt damage to you this turn.

Vigilance

Whenever Sun Titan enters the battlefield or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

{T}: Add {C}.

{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

+2: Create two 0/1 black Thrull creature tokens.

+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.

-10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.

Tevesh Szat, Doom of Fools can be your commander.

Partner

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Creature tokens you control have vigilance and lifelink.

Other creatures you control get +0/+1.

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.