Disguised Blast

You send a bolt of magical force that is cloaked in illusion magic at one creature that you can see within range. The target must make an Intelligence saving throw, taking 7d4 psychic damage on a failed save or half as much damage on a successful one. If the target succeeds the save, they know that you are the one that casted the spell, and automatically save against this spell for the next hour.
A target automatically saves against this spell if they don't rely on sight, as with blindsight, or can see through illusions, as with truesight. This spell does double damage to surprised creatures.

At Higher Levels. When you cast this spell using a slot of 4th level or higher, the damage increases by 2d4 for each slot above 3rd.