Incinerate

You channel agonizing flames, wreathing a creature you can see within range. At the start of each of its turns, the target must make a Dexterity saving throw, taking 10d6 fire damage on a failure. On a success, it takes half as much damage and the spell ends for that creature. While a target is on fire, it casts bright light for 30 feet and dim light for an additional 30 feet.

As a bonus action, you can spread the flames from any target creature to another within 10 feet of it, making that creature an additional target. If damage from this spell reduces a target to 0 hit points, the target is turned to ash.