Empty the Pits

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Create X tapped 2/2 black Zombie creature tokens.

Archers of Qarsi

Defender
Reach (This creature can block creatures with flying.)

Dead Drop

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target player sacrifices two creatures of their choice.

Brokkos, Apex of Forever

Mutate {2}{U/B}{G}{G} (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.)
Trample
You may cast Brokkos, Apex of Forever from your graveyard using its mutate ability.

Become Immense

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target creature gets +6/+6 until end of turn.

Abomination of Gudul

Flying
Whenever Abomination of Gudul deals combat damage to a player, you may draw a card. If you do, discard a card.
Morph {2}{B}{G}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Death Frenzy

All creatures get -2/-2 until end of turn. Whenever a creature dies this turn, you gain 1 life.

Sidisi, Brood Tyrant

Whenever Sidisi, Brood Tyrant enters or attacks, mill three cards.
Whenever one or more creature cards are put into your graveyard from your library, create a 2/2 black Zombie creature token.

Vorosh, the Hunter

Flying
Whenever Vorosh, the Hunter deals combat damage to a player, you may pay {2}{G}. If you do, put six +1/+1 counters on Vorosh.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.