Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Blasting Station

{T}, Sacrifice a creature: This artifact deals 1 damage to any target.
Whenever a creature enters, you may untap this artifact.

Attrition

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

Brood Butcher

Devoid (This card has no color.)
When this creature enters, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}."
{B}{G}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.

Kenrith, the Returned King

{R}: All creatures gain trample and haste until end of turn.
{1}{G}: Put a +1/+1 counter on target creature.
{2}{W}: Target player gains 5 life.
{3}{U}: Target player draws a card.
{4}{B}: Put target creature card from a graveyard onto the battlefield under its owner's control.

Chittering Witch

When this creature enters, create a number of 1/1 black Rat creature tokens equal to the number of opponents you have.
{1}{B}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.