Dark Fire Bolt

You hurl a mote of dark fire at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 1d10 fire damage. In dark and dim places the fire is Invisibl. And if the target is hit in dark and dim places, it takes addictional necrotic damage equal to your spellcasting ability modifier. The Dark fire can't ignite anything. 

This spell's damage increases by 1d10 when you reach 5th level (2d10), 11th level (3d10), and 17th level (4d10).