Super Saiyan Weiss time? Well, more like Super Hitler Weiss as our sweet boy goes unconscious & the original villain takes control.
this is basically what I was looking for in the comments so far, glad i'm not the only one who thought it'd be a setup for the OG Weiss to come back for a bit. the story's been pretty consistent about the fact he's been lurking under the surface & influencing the MC's feelings towards him, it'd make sense (in a way) if getting his brain rattled like that knocks him out without incapacitating him & thus the 'evil spirit' gets to take over (and talk shit during the fight to make sure MC and Hero-kun can't become friends and actually communicate in any meaningful way for however many volumes in the future lol)
wouldn't he make them 50/50 then increased to 100/0 at point of attack? or it's set and forget thing?
that's the kind of clever tactic i'd think he would've been doing from the start if the magic he uses were continuous-use type things that he can modify on the fly, but it really seems like he's mostly only able to use simple, single-command type logic in spell creation that can't be changed after the fact, hence why flight magic (a complex, innately 'changeable' spell) is so hard for him & he doesn't just create 'complex' unnatural walls that he can move around to use as permanent barriers/invisible swords/temu flight magic lol