Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Macabre Waltz

Return up to two target creature cards from your graveyard to your hand, then discard a card.

Plague Mare

Plague Mare can't be blocked by white creatures.
When Plague Mare enters, creatures your opponents control get -1/-1 until end of turn.

Pharika's Cure

Pharika's Cure deals 2 damage to target creature and you gain 2 life.

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

March of the Returned

Return up to two target creature cards from your graveyard to your hand.

Sorin's Thirst

Sorin's Thirst deals 2 damage to target creature and you gain 2 life.

Crippling Blight

Enchant creature
Enchanted creature gets -1/-1 and can't block.

Shadow Slice

Target opponent loses 3 life.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.