Swamp

Mesmeric Fiend

When this creature enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Oblivion Strike

Devoid (This card has no color.)
Exile target creature.

Scrounger of Souls

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Frightcrawler

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Threshold — As long as there are seven or more cards in your graveyard, this creature gets +2/+2 and can't block.

Befoul

Destroy target land or nonblack creature. It can't be regenerated.

Ridged Kusite

{1}{B}, {T}, Discard a card: Target creature gets +1/+0 and gains first strike until end of turn.

Phyrexian Rager

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

Dash Hopes

When you cast this spell, any player may pay 5 life. If a player does, counter Dash Hopes.
Counter target spell.

Sinister Strength

Enchant creature
Enchanted creature gets +3/+1 and is black.

Distress

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

Fume Spitter

Sacrifice this creature: Put a -1/-1 counter on target creature.

Midnight Recovery

Return target creature card from your graveyard to your hand.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Ostracize

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

Blistergrub

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When this creature dies, each opponent loses 2 life.