Tallyman of Nurgle

Lifelink
The Seven-fold Chant — At the beginning of your end step, if a creature died this turn, you draw a card and you lose 1 life. If seven or more creatures died this turn, instead you draw seven cards and you lose 7 life.

Ulcerate

Target creature gets -3/-3 until end of turn. You lose 3 life.

Patron of the Vein

Flying
When Patron of the Vein enters, destroy target creature an opponent controls.
Whenever a creature an opponent controls dies, exile it and put a +1/+1 counter on each Vampire you control.

Grim Wanderer

Flash
Tragic Backstory — Cast this spell only if a creature died this turn.

Disfigure

Target creature gets -2/-2 until end of turn.

Gravelighter

Flying
When Gravelighter enters, draw a card if a creature died this turn. Otherwise, each player sacrifices a creature of their choice.

Swamp

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters, destroy target nonartifact, nonblack creature.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Slaughter Specialist

When Slaughter Specialist enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Slaughter Specialist.

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters, destroy up to one target creature and target player mills three cards.

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Bloodchief's Thirst

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Destroy target creature or planeswalker with mana value 2 or less. If this spell was kicked, instead destroy target creature or planeswalker.

Malakir Cullblade

Whenever a creature an opponent controls dies, put a +1/+1 counter on Malakir Cullblade.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Cut Down

Destroy target creature with total power and toughness 5 or less.

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Toshiro Umezawa

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever a creature an opponent controls dies, you may cast target instant card from your graveyard. If that spell would be put into a graveyard, exile it instead.

Bile Blight

Target creature and all other creatures with the same name as that creature get -3/-3 until end of turn.

Gatekeeper of Malakir

Kicker {B} (You may pay an additional {B} as you cast this spell.)
When this creature enters, if it was kicked, target player sacrifices a creature of their choice.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.