Terra, Herald of Hope

Trance — At the beginning of combat on your turn, mill two cards. Terra gains flying until end of turn.
Whenever Terra deals combat damage to a player, you may pay {2}. When you do, return target creature card with power 3 or less from your graveyard to the battlefield tapped.

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

Sun Titan

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

Sol Ring

Victimize

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

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Celes, Rune Knight

When Celes enters, discard any number of cards, then draw that many cards plus one.
Whenever one or more other creatures you control enter, if one or more of them entered from a graveyard or was cast from a graveyard, put a +1/+1 counter on each creature you control.

Boros Signet

Tenacious Underdog

Blitz—{2}{B}{B}, Pay 2 life. (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)
You may cast this card from your graveyard using its blitz ability.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Rakdos Signet

Orzhov Signet

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.