Confusion spells are okay, but they're not terribly confusing. You just lose control of your character and depending attack whatever is closest.
What if it was actually confusing?
A character who becomes confused gets some mixture of client-side only effects. Think like the drug effects that only the drug users see. Stuff like random VFX effects, from sparkles and Faerzress explosions to hellball effects. Combat sword clashing sounds, people talking, etc.
Another cool aspect would be PCs (and NPCs) visually changed. Names either swap to generic ones or vanish, their models swap with other ones. Maybe even remove language comprehension. Literally leaving a character (and player) confused. When the confusion ends, all goes back to normal.