The issue
Anyone who’s fought Maine at least once since he came out should already have a good idea of what my suggestion is aiming at. Maine is a user of plasma magic, which he imbues onto his greatbow, a strength weapon. However, during his fight, he only ever uses his greatbow, and his plasma magic appears only as imbuement. Then, when Maine inevitabely uses Bow breaker, the entire fight turns into a snoozefest, as the move stops him from using his bow, his only weapon, making him just stand there until the player kills him.
The solution
Simply giving Maine a moveset for his plasma magic should solve the issue. I get that the greatbow is his main thing, and this expanded moveset isn’t supposed to overtake it. Thus, Maine will use his plasma magic only and exclusively while his bow is on cooldown following Bow breaker being used, and will stop using it when he can use his bow again. This should keep the greatbow as his quirk, while also not ending the fight the moment he uses Bow breaker.
The moveset
I think 4 generic spells is good enough to keep his fight interesting but not shift the focus from the greatbow.
Ionized shot
Singular 60% blast and explosion size arrow-shaped blast.
Gamma ambush
Three 60% explosion size spear-shaped pillar explosions.
Scorching shower
Maximum amount barrage spells, don’t yet know the settings it has.
Ultimate art: Deadly plasma archery
Twenty 100% blast and explosion size arrow-shaped blasts with ultimate art.