Skrelv's Hive

At the beginning of your upkeep, you lose 1 life and create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."
Corrupted — As long as an opponent has three or more poison counters, creatures you control with toxic have lifelink.

Assault Intercessor

First strike, menace
Chainsword — Whenever a creature an opponent controls dies, that player loses 2 life.

Plains

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Kokusho, the Evening Star

Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Transmogrant's Crown

Equipped creature gets +2/+0.
Whenever equipped creature dies, draw a card.
Equip {2} or {B}

Norn's Wellspring

Whenever a creature you control dies, scry 1 and put an oil counter on Norn's Wellspring.
{1}, {T}, Remove two oil counters from Norn's Wellspring: Draw a card.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Teysa Karlov

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Creature tokens you control have vigilance and lifelink.

Malakir Mire

Malakir Mire enters tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Archfiend of the Dross

Flying
Archfiend of the Dross enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from Archfiend of the Dross. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}