@ThomasMarkov There is, as far as I can tell, a single chink in the armor of my plan beyond getting the spell to land and not saved against: Feeblemind
The target takes 4d6 psychic damage and must make an Intelligence saving throw. On a failed save, the creature’s Intelligence and Charisma scores become 1. The creature can’t cast spells, activate magic items, understand language, or communicate in any intelligible way. The creature can, however, identify its friends, follow them, and even protect them. At the end of every 30 days, the creature can repeat its saving throw against this spell.