Razaketh, the Foulblooded

Flying, trample
Pay 2 life, Sacrifice another creature: Search your library for a card, put that card into your hand, then shuffle.

Athreos, God of Passage

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
Whenever another creature you own dies, return it to your hand unless target opponent pays 3 life.

Snow-Covered Swamp

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Snow-Covered Plains

Immortal Servitude

Return each creature card with mana value X from your graveyard to the battlefield.

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.

Shadowborn Apostle

A deck can have any number of cards named Shadowborn Apostle.
{B}, Sacrifice six creatures named Shadowborn Apostle: Search your library for a Demon creature card, put it onto the battlefield, then shuffle.

Edgewalker

Cleric spells you cast cost {W}{B} less to cast. This effect reduces only the amount of colored mana you pay. (For example, if you cast a Cleric spell with mana cost {1}{W}, it costs {1} to cast.)

Dreadfeast Demon

Flying
At the beginning of your end step, sacrifice a non-Demon creature. If you do, create a token that's a copy of Dreadfeast Demon.

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.