Have

Swamp

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Clay Revenant

Clay Revenant enters tapped.
{2}{B}: Return Clay Revenant from your graveyard to your hand.

Mind Rot

Desperate Bloodseeker

Lifelink
When Desperate Bloodseeker enters, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Bad Moon

Go for the Throat

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Gixian Skullflayer

At the beginning of your upkeep, if there are three or more creature cards in your graveyard, put a +1/+1 counter on Gixian Skullflayer.

Gix's Caress

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Gnawing Vermin

When Gnawing Vermin enters, target player mills two cards.
When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

Heartless Pillage

Target opponent discards two cards.
Raid — If you attacked this turn, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Battlefield Butcher

{5}, {T}: Each opponent loses 2 life. This ability costs {1} less to activate for each creature card in your graveyard.