Attrition

{B}, Sacrifice a creature: Destroy target nonblack creature.

Ashnod's Altar

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Sauron, the Dark Lord

Ward—Sacrifice a legendary artifact or legendary creature.
Whenever an opponent casts a spell, amass Orcs 1.
Whenever an Army you control deals combat damage to a player, the Ring tempts you.
Whenever the Ring tempts you, you may discard your hand. If you do, draw four cards.

Carnage Altar

Corrupted Conviction

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.