Call a Surprise Witness

Return target creature card with mana value 3 or less from your graveyard to the battlefield. Put a flying counter on it. It's a Spirit in addition to its other types.

Steamcore Scholar

Flying, vigilance
When this creature enters, draw two cards. Then discard two cards unless you discard an instant or sorcery card or a creature card with flying.

Olag, Ludevic's Hubris

As this creature transforms into Olag, Ludevic's Hubris, it becomes a copy of a creature card exiled with it, except its name is Olag, Ludevic's Hubris, it's 4/4, and it's a legendary blue and black Zombie in addition to its other colors and types. Put a number of +1/+1 counters on Olag equal to the number of creature cards exiled with it.

Ludevic, Necrogenius

Whenever Ludevic enters or attacks, mill a card.
{X}{U}{U}{B}{B}, Exile X creature cards from your graveyard: Transform Ludevic. X can't be 0. Activate only as a sorcery.

Ludevic, Necrogenius // Olag, Ludevic's Hubris

Tome Scour

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Revenge

Double your life total. Target opponent loses half their life, rounded up.

Revival

Return target creature card with mana value 3 or less from your graveyard to the battlefield.

Revival // Revenge

Island

Swamp

Renegade Reaper

Flying
When this creature enters, mill four cards. If at least one Angel card is milled this way, you gain 4 life. (To mill a card, put the top card of your library into your graveyard.)

Atraxa, Grand Unifier

Flying, vigilance, deathtouch, lifelink
When Atraxa enters, reveal the top ten cards of your library. For each card type, you may put a card of that type from among the revealed cards into your hand. Put the rest on the bottom of your library in a random order. (Artifact, battle, creature, enchantment, instant, land, planeswalker, and sorcery are card types.)

Avacyn, Angel of Hope

Flying, vigilance, indestructible
Other permanents you control have indestructible.

Ruthless Lawbringer

When this creature enters, you may sacrifice another creature. When you do, destroy target nonland permanent.

Contaminated Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle.
Cycling {W}{U}{B} ({W}{U}{B}, Discard this card: Draw a card.)

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Avacyn, the Purifier

Flying
When this creature transforms into Avacyn, the Purifier, it deals 3 damage to each other creature and each opponent.

Archangel Avacyn

Flash
Flying, vigilance
When Archangel Avacyn enters, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.

Archangel Avacyn // Avacyn, the Purifier

Isolated Chapel

This land enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Seachrome Coast

This land enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Flickerwisp

Flying
When this creature enters, exile another target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Plains

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Resolute Archangel

Flying
When this creature enters, if your life total is less than your starting life total, it becomes equal to your starting life total.

Unburial Rites

Return target creature card from your graveyard to the battlefield.
Flashback {3}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.