Deathmark

Swamp

Slay

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

Soot Imp

Flying
Whenever a player casts a nonblack spell, that player loses 1 life.

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.

Bereavement

Whenever a green creature dies, its controller discards a card.

Yawgmoth's Edict

Whenever an opponent casts a white spell, that player loses 1 life and you gain 1 life.

Marauding Knight

Protection from white
This creature gets +1/+1 for each Plains your opponents control.

Slithery Stalker

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When this creature enters, exile target green or white creature an opponent controls.
When this creature leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Putrefaction

Whenever a player casts a green or white spell, that player discards a card.

Deathgrip

Painter's Servant

As this creature enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Stromgald Cabal

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

Distorting Lens

{T}: Target permanent becomes the color of your choice until end of turn.

Perish

Destroy all green creatures. They can't be regenerated.

Ascendant Evincar

Flying (This creature can't be blocked except by creatures with flying or reach.)
Other black creatures get +1/+1.
Nonblack creatures get -1/-1.

Nature's Ruin

Eastern Paladin

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

Gloom

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

Virtue's Ruin

Irini Sengir

Green enchantment spells and white enchantment spells cost {2} more to cast.

Thrull Wizard

{1}{B}: Counter target black spell unless that spell's controller pays {B} or {3}.