Orzhov Signet

Blood Bairn

Sacrifice another creature: Blood Bairn gets +2/+2 until end of turn.

Azorius Signet

Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Dimir Signet

Chronozoa

Flying
Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Chronozoa dies, if it had no time counters on it, create two tokens that are copies of it.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Solemnity

Players can't get counters.
Counters can't be put on artifacts, creatures, enchantments, or lands.

Island

Plains

Glimpse of Freedom

Draw a card.
Escape—{2}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Viscera Seer

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

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Dark Prophecy

Whenever a creature you control dies, you draw a card and you lose 1 life.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Zulaport Cutthroat

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