Night of Souls' Betrayal

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Jet Medallion

Black spells you cast cost {1} less to cast.

Defile

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

Massacre Wurm

When Massacre Wurm enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Make Obsolete

Creatures your opponents control get -1/-1 until end of turn.

Maha, Its Feathers Night

Flying, trample
Ward—Discard a card.
Creatures your opponents control have base toughness 1.

Sol Ring

Kaervek, the Spiteful

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Swamp

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.