Responses
he's also extremely weak due to the injuries he got when he was inside Ume's mind, so add that to the extreme stress and anxiety he was feeling due to the isolation (plus hunger that actually does affect him now, i mean imagine going drom delicious full day meals to almost nothing or just prison meals) and you get an extremely weak sorcerer
just a lot of things piled up that practically renders him incapable of doing any sorcery
Oh my gosh that made me tear up… i forgor about the plot a bit but isnt he just magic deficient? If so he can just ask umehiko