Have

Necrite

Whenever Necrite attacks and isn't blocked, you may sacrifice it. If you do, destroy target creature defending player controls. It can't be regenerated.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Swamp

Desecration Elemental

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever a player casts a spell, sacrifice a creature.

Peat Bog

Peat Bog enters the battlefield tapped with two depletion counters on it.
{T}, Remove a depletion counter from Peat Bog: Add {B}{B}. If there are no depletion counters on Peat Bog, sacrifice it.

Dark Ritual

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Sadistic Glee

Enchant creature
Whenever a creature dies, put a +1/+1 counter on enchanted creature.

Death Denied

Return X target creature cards from your graveyard to your hand.

Forsaken Wastes

Players can't gain life.
At the beginning of each player's upkeep, that player loses 1 life.
Whenever Forsaken Wastes becomes the target of a spell, that spell's controller loses 5 life.

Mindstab Thrull

Whenever Mindstab Thrull attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Armor Thrull

{T}, Sacrifice Armor Thrull: Put a +1/+2 counter on target creature.

Basal Thrull

Blood Pet

Thrull Surgeon

{1}{B}, Sacrifice Thrull Surgeon: Look at target player's hand and choose a card from it. That player discards that card. Activate only as a sorcery.