Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Malefic Scythe

Malefic Scythe enters with a soul counter on it.
Equipped creature gets +1/+1 for each soul counter on Malefic Scythe.
Whenever equipped creature dies, put a soul counter on Malefic Scythe.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Swamp

Parasitic Implant

Enchant creature
At the beginning of your upkeep, enchanted creature's controller sacrifices it and you create a 1/1 colorless Phyrexian Myr artifact creature token.

Phyrexian Broodlings

{1}, Sacrifice a creature: Put a +1/+1 counter on Phyrexian Broodlings.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Douse in Gloom

Douse in Gloom deals 2 damage to target creature and you gain 2 life.

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Myr Sire

When Myr Sire dies, create a 1/1 colorless Phyrexian Myr artifact creature token.

Thriving Moor

Thriving Moor enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Phyrexian Debaser

Flying
{T}, Sacrifice Phyrexian Debaser: Target creature gets -2/-2 until end of turn.

Phyrexian Gargantua

When Phyrexian Gargantua enters, you draw two cards and you lose 2 life.

Entomber Exarch

When Entomber Exarch enters, choose one —
• Return target creature card from your graveyard to your hand.
• Target opponent reveals their hand. You choose a noncreature card from it. That player discards that card.