Thunder Dragons Fury

You close your eyes and extend your arms, calling upon the powers of Fey Thunderstorms and chenneling them into the horrifying visage of a dragon made of electricity all around you. Every beat of the wings sounds like the crack of thunder. All creatures of your choice within range must make a Constitution saving throw or take 9d6 thunder damage and become frightened, or half as much damage on a successful save, and resist the frightened condition. Any creature that successfully saves is immune to the frightened condition from this spell for 24 hours.

At Higher Levels

When you cast this spell using a spell slot of 7th level or higher, the damage increases by 2d6 for each slot level above 6th.