Draven's Corpse Detonation

Choose one corpse within range that you can see, causing the remains to violently erupt with necrotic energy. The corpse along with all non-magical items worn by it are destroyed by the explosion. If targeting an undead creature that is not controlled by you that creature can make a Constitution saving throw, causing the casting of the spell to fail on a success. The creature automatically succeeds on this save if they have 20 hit points or more.

Each creature in a 20-foot-radius Sphere centered on the corpse makes a Dexterity saving throw, taking 5d8 Fire damage and 5d8 Necrotic damage on a failed save or half as much damage on a successful one. Flammable objects in the area that aren’t being worn or carried start burning.

Using a Higher-Level Spell Slot. The Fire damage and the Necrotic damage increase by 1d8 for each spell slot level above 5.