Astral Shroud

You bathe yourself in a protective magical force that is the color of your elemental type, and it drapes around you as
though it were a shroud. If a creature hits you with a melee attack that creature must make a Dexterity saving throw. The creature takes 2d10 damage of the type associated with your Kitsune ancestry on a failed save, or half as much damage on a successful one. If you are a time Kitsune, instead of doing normal damage, the damage you deal is in the years of that target’s age. An example of this is if you rolled a 15, then that target has become 15 years older. A lesser restoration spell can restore a creature’s age to normal.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d10 for each slot level above 3rd.