Swamp

Dunerider Outlaw

Protection from green
At the beginning of each end step, if this creature dealt damage to an opponent this turn, put a +1/+1 counter on it.

Stench of Evil

Destroy all Plains. For each land destroyed this way, Stench of Evil deals 1 damage to that land's controller unless they pay {2}.

Gloom

White spells cost {3} more to cast.
Activated abilities of white enchantments cost {3} more to activate.

Execute

Destroy target white creature. It can't be regenerated.
Draw a card.

Talara's Bane

Target opponent reveals their hand. You choose a green or white creature card from it. You gain life equal to that creature card's toughness, then that player discards that card.

Deathmark

Howl from Beyond

Target creature gets +X/+0 until end of turn.

Dread of Night

Black Knight

First strike (This creature deals combat damage before creatures without first strike.)
Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)

Eastern Paladin

{B}{B}, {T}: Destroy target green creature.

Frightcrawler

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

Deathgrip

Dauthi Horror

Shadow (This creature can block or be blocked by only creatures with shadow.)
This creature can't be blocked by white creatures.

Dross Golem

Affinity for Swamps (This spell costs {1} less to cast for each Swamp you control.)
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Sinister Strength

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

Stromgald Cabal

{T}, Pay 1 life: Counter target white spell.

Western Paladin

{B}{B}, {T}: Destroy target white creature.

Knight of Stromgald

Protection from white
{B}: This creature gains first strike until end of turn.
{B}{B}: This creature gets +1/+0 until end of turn.