Bolt of flesh melting

You attempt to melt the flesh off of one creature’s bones, that you can see within range. The target must make a Dexterity saving throw. It takes 8d6 acid damage on a failed save, or half as much damage on a successful one. On a failed save, the target also burns for the spell’s duration. At the end of each of its turns, the target repeats the saving throw. It takes 4d6 acid damage on a failed save, and the spell ends on a successful one. This acid can’t be washed away by nonmagical means.

If damage from this spell kills a target, the target is turned to a pile of bones in a puddle of melted goop.