Doom Blade

Nameless Inversion

Changeling (This card is every creature type.)
Target creature gets +3/-3 and loses all creature types until end of turn.

Tomb of Urami

{T}: Add {B}. Tomb of Urami deals 1 damage to you if you don't control an Ogre.
{2}{B}{B}, {T}, Sacrifice all lands you control: Create Urami, a legendary 5/5 black Demon Spirit creature token with flying.

Victim of Night

Destroy target non-Vampire, non-Werewolf, non-Zombie creature.

Infest

All creatures get -2/-2 until end of turn.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Phyrexian Totem

{T}: Add {B}.
{2}{B}: Phyrexian Totem becomes a 5/5 black Phyrexian Horror artifact creature with trample until end of turn.
Whenever Phyrexian Totem is dealt damage, if it's a creature, sacrifice that many permanents.

Hymn to Tourach

Target player discards two cards at random.

Sign in Blood

Target player draws two cards and loses 2 life.

Duress

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

Blight

Enchant land
When enchanted land becomes tapped, destroy it.

Raven's Crime

Target player discards a card.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Swamp

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control of their choice, then sacrifices a third of the lands they control of their choice. Round up each time.

Nether Spirit

At the beginning of your upkeep, if Nether Spirit is the only creature card in your graveyard, you may return Nether Spirit to the battlefield.

Genju of the Fens

Enchant Swamp
{2}: Until end of turn, enchanted Swamp becomes a 2/2 black Spirit creature with "{B}: This creature gets +1/+1 until end of turn." It's still a land.
When enchanted Swamp is put into a graveyard, you may return Genju of the Fens from your graveyard to your hand.