Belphegor´s New Moon

You float up and curls yourself, creating an large dark new moon, which you then sends floating to a point within range, erupting in a whirlwind of frost and darkness. Each creature in a 60-foot-radius centered on that point must make a Wisdom saving throw. On a failure, a creature takes 4d8 cold damage plus 4d8 psychic damage. On a success, a creature takes half as much damage. In addition, the area is covered with dim light for 1 minute.

Using a Higher-Level Spell Slot. The damage (both cold and psychic) increases by 1d8 for each spell slot level above 6.