Vidia's Vindictive Vengeance

You draw upon energies from the lost souls within the Feywild. The panic of the Feylost, the manic energy of those driven insane, and the fear and anguish of those tortured by Sylvan tricksters all bubble together into a miasma of pink and purple negative energy.

As an action, you can unleash a 60-foot cone of psychic energy. Each creature in that area must make a Dexterity saving throw. On a failed save, each creature takes 12d6 psychic damage or half as much damage on a successful save. 

At Higher Levels. When you cast this spell using a spell slot of 8th Level or higher, the damage increases by 2d6 for each slot level above 7th.