Darkened Amaterasu Strike

You hurl a mote of black fire at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 5d10 fire damage. A flammable object hit by this spell ignites if it isn't being worn or carried.

This spell's damage increases by 2d10 when you reach 6th level (6d10), 14th level (8d10), and 19th level (10d10).