Tyrannical Pitlord

Flying, trample
As this creature enters, choose another creature you control.
The chosen creature gets +3/+3 and has flying.
When this creature leaves the battlefield, sacrifice the chosen creature.

Writhing Necromass

This spell costs {1} less to cast for each creature card in your graveyard.
Deathtouch

Knight of Dusk's Shadow

Menace (This creature can't be blocked except by two or more creatures.)
Your opponents can't gain life.
{1}{B}: This creature gets +1/+1 until end of turn.

Phyrexian Vivisector

Whenever a creature you control dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Sengir Connoisseur

Flying
Whenever one or more other creatures die, put a +1/+1 counter on this creature. This ability triggers only once each turn.

Phyrexian Rager

When this creature enters, you draw a card and you lose 1 life.

Extinguish the Light

Destroy target creature or planeswalker. If its mana value was 3 or less, you gain 3 life.

Totally Merciless

Battle-Rage Blessing

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Weatherlight Compleated

Flying
As long as Weatherlight Compleated has four or more phyresis counters on it, it's a Phyrexian creature in addition to its other types.
Whenever a creature you control dies, put a phyresis counter on Weatherlight Compleated. Then draw a card if it has seven or more phyresis counters on it. If it doesn't, scry 1.

Eerie Soultender

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
{4}{B}, Exile this card from your graveyard: Return another target creature card from your graveyard to your hand.

Braids's Frightful Return

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You may sacrifice a creature. If you do, each opponent discards a card.
II — Return target creature card from your graveyard to your hand.
III — Target opponent may sacrifice a nonland, nontoken permanent of their choice. If they don't, they lose 2 life and you draw a card.

Swamp

Pilfer

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.