Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Beckon Apparition

Exile target card from a graveyard. Create a 1/1 white and black Spirit creature token with flying.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Swamp

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Exhume

Each player puts a creature card from their graveyard onto the battlefield.

Nip Gwyllion

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

Edge of the Divinity

Enchant creature
As long as enchanted creature is white, it gets +1/+2.
As long as enchanted creature is black, it gets +2/+1.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Nightsky Mimic

Whenever you cast a spell that's both white and black, Nightsky Mimic has base power and toughness 4/4 until end of turn and gains flying until end of turn.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)