Celestial Rainbow Explosion

A bright streak of multi-colored light flashes from your pointing finger to a point you choose within range and then erupts into a fireworks explosion of color and light. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 8d6 radiant damage on a failed save, or half as much damage on a successful one.

The rainbow spreads around corners. On a failed save, the creature becomes charmed for the duration. While charmed by this spell, the creature is incapacitated and has a speed of 0.

The spell ends for an affected creature if it takes any damage or if someone else uses an action to shake the creature out of its stupor.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.