Angel's Feathers

You create six light-infused feathers. Each feather targets a creature of your choice that you can see within range. The target makes a Dexterity saving throw with a DC of 18. On a fail, a feather deals 3d8 light damage to its target. On a success, the target takes half damage.

Upon taking damage during the casting process the spell is canceled and you roll a d20. Get a 1 and the spell backfires dealing 10d8 to the spell caster. Get a 20 and something miraculous happens.