Defile

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

Refurbished Familiar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Refurbished Familiar enters, each opponent discards a card. For each opponent who can't, you draw a card.

Blood Fountain

When Blood Fountain enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{3}{B}, {T}, Sacrifice Blood Fountain: Return up to two target creature cards from your graveyard to your hand.

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Cast Down

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

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.")

Duress

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

Lembas

When Lembas enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Lembas: You gain 3 life.
When Lembas is put into a graveyard from the battlefield, its owner shuffles it into their library.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.