Swamp

Pilfer

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

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Flitting Guerrilla

Flying
When Flitting Guerrilla dies, each player mills two cards. Then you may exile Flitting Guerrilla. When you do, put target creature or battle card from your graveyard on top of your library. (To mill two cards, a player puts the top two cards of their library into their graveyard.)

Hero's Downfall

Duress

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

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.

Prickle Faeries

Flying
At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Prickle Faeries deals 2 damage to them.

Invasion of Eldraine

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Eldraine enters, target opponent discards two cards.