+darling (4)
Target creature gets -2/-2 until end of turn. If it's night, that creature gets -13/-13 until end of turn instead.
Alliance — Whenever another creature you control enters, you gain 1 life.
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.
All creatures get -3/-3 until end of turn.
You may cast a spell with mana value 3 or less from your hand without paying its mana cost.
Gatherer works better in the Companion app!