Time of Heroes

Each creature you control with a level counter on it gets +2/+2.

Hand of Emrakul

You may sacrifice four Eldrazi Spawn rather than pay this spell's mana cost.
Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.)

Totem-Guide Hartebeest

When this creature enters, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle.

Transcendent Master

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 6-11
6/6
Lifelink
LEVEL 12+
9/9
Lifelink, indestructible

Umbra Mystic

Auras attached to permanents you control have umbra armor. (If an enchanted permanent you control would be destroyed, instead remove all damage from it and destroy an Aura attached to it.)

Wall of Omens

Defender
When this creature enters, draw a card.

Aura Finesse

Attach target Aura you control to target creature.
Draw a card.

Cast Through Time

Instant and sorcery spells you control have rebound. (Exile the spell as it resolves if you cast it from your hand. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Champion's Drake

Flying
This creature gets +3/+3 as long as you control a creature with three or more level counters on it.

Coralhelm Commander

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-3
3/3
Flying
LEVEL 4+
4/4
Flying
Other Merfolk creatures you control get +1/+1.

Crab Umbra

Enchant creature
{2}{U}: Untap enchanted creature.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Deprive

As an additional cost to cast this spell, return a land you control to its owner's hand.
Counter target spell.

Kozilek, Butcher of Truth

When you cast this spell, draw four cards.
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents of their choice.)
When Kozilek is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Distortion Strike

Target creature gets +1/+0 until end of turn and can't be blocked this turn.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Domestication

Enchant creature
You control enchanted creature.
At the beginning of your end step, if enchanted creature's power is 4 or greater, sacrifice this Aura.

Dormant Gomazoa

Flying
This creature enters tapped.
This creature doesn't untap during your untap step.
Whenever you become the target of a spell, you may untap this creature.

Rise of the Eldrazi