Corpse Explosion

Target a undead creature you control or a Corpse within 90ft of you. The Target explodes into a 20 ft radius sphere.

Each creature in the 20 ft radius sphere centered on the corpse must make a Dexterity saving throw.

A target takes 3d10 Necrotic damage  + Your spellcasting modifier on a failed save or half as much damage on a successful one.

At Higher Levels. When you cast this spell using a 3rd level spell slot or higher, the damage increases by 1d10, for each slot level above 2nd