Three incorporeal, dimly glowing lemmata appear and begin orbiting the target's head. As a bonus action, you may activate a lemma. When you do so, the target gains the ability to replace a named spell or named effect in the text of another spell the target casts with a named spell of the target's choice. The target must have the latter spell either prepared, written in their spellbook, or present on a spell scroll in their possession. An activated lemma is discharged and disappears when it is used this way, or at the end of the target's next turn, whichever happens first.