You surround yourself with crackling necrotic power, and unleash it in a tempest of dark lightning around you. Choose one ability when you cast this spell. Each other creature in a 20-foot radius sphere centered on you must succeed on a Dexterity saving throw or take 3d6 necrotic damage and become cursed until the spell ends. A creature that succeeds on its saving throw takes half as much damage and isn’t cursed. A creature cursed with this spell takes an extra 1d6 necrotic damage whenever you hit it with an attack and has disadvantage on ability checks it makes with the chosen ability.   A remove curse cast on a target ends this spell’s effects on that target.