Bahamut’s cleansing light

A gate to ???? Opens and bahamut sends a cleansing light that destroys evil. The spell destroys anything of the evil alignment under 100 hp. If the enemy has hp greater than 100 it make a charisma saving throw. On a failed save it does 20d6 Damadge and on a successful save it does half. Feats sutch as evasion don’t counter this spell