A dark streak of fire shoots from your pointing finger to a point you choose within range then blossoms with a low roar into an explosion of black fire.
Each creature in a 10-foot radius must make a Dexterity saving throw.
A target takes 4d6 fire + 3d6 necrotic damage on a failed save, or half as much damage on a successful one.
Additionally, on a fail, their hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the target finishes a long rest.
The black fire spreads around corners. It ignites flammable objects and rots plants in the area that aren’t being worn or carried.