Brainer
Weapon (mace), legendary (requires attunement)
You gain a +3 bonus to attack and damage rolls made with this magic weapon and it deals an extra 1d6 psychic damage to any target it hits.
The mace has 12 charges and regains 1d10 + 2 expended charges daily at dawn. While holding the mace, you can expend 1 or more of its charges to cast one of the following spells from it (save DC 18): detect thoughts (1 charge), confusion (3 charges), or modify memory (4 charges).
Annihilate Mind. When you hit a creature with this mace, you can expend 4 charges to force the creature to make a DC 18 Intelligence saving throw. On a failed save, the creature takes an extra 6d6 psychic damage and is stunned until the end of your next turn. Additionally, while stunned in this way, the creature has disadvantage on its saving throws to resist any spell you cast from this mace.
Crafted in the spinal baths and psychic forges of Cephalarr aka the Brain Butcher, the Cranium Crasher, the Dome Demolisher, the Ego Eradicator, the Faculty Fleecer, the Genius Gutter, the Head Harmer, the Imagination Immolator, the Mind Maimer, the Reason Ravager, the Thought Thumper, the Wrinkle Wrecker, and so forth.