Astrid's Head Popper

Choose a point within range. Psychic energy explodes there and each creature in a 20-foot-radius sphere centered on that point = Intelligence saving throw. A creature with an Intelligence score of 2 or lower is not affected by this spell. On a fail save = 8d6 psychic damage, or half as much damage on a successful one.

After a failed save, targets have incoherent thoughts for 1 minute and must subtract a d6 from all attack rolls and ability checks, as well as saving throws to maintain concentration. The targets can make an Intelligence saving throw at the end of each of their turns, ending the effect on a success.