Unholy Indenture

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control with a +1/+1 counter on it.

Swamp

Odylic Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Whenever Odylic Wraith deals damage to a player, that player discards a card.

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Triangle of War

{2}, Sacrifice Triangle of War: Target creature you control fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Cuombajj Witches

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.

Pit Scorpion

Whenever Pit Scorpion deals damage to a player, that player gets a poison counter. (A player with ten or more poison counters loses the game.)

Dirge of Dread

All creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)
When you cycle Dirge of Dread, you may have target creature gain fear until end of turn.

Restless Dead

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Horrible Hordes

Rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Skull Catapult

{1}, {T}, Sacrifice a creature: Skull Catapult deals 2 damage to any target.

Feast of Succession

All creatures get -4/-4 until end of turn. You become the monarch.

Blight

Enchant land
When enchanted land becomes tapped, destroy it.

Bankrupt in Blood

As an additional cost to cast this spell, sacrifice two creatures.
Draw three cards.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Blighted Shaman

{T}, Sacrifice a Swamp: Target creature gets +1/+1 until end of turn.
{T}, Sacrifice a creature: Target creature gets +2/+2 until end of turn.

Kaervek's Hex

Kaervek's Hex deals 1 damage to each nonblack creature and an additional 1 damage to each green creature.