The end? No, not the end. Going for another asspull and let mob enemy go "admit your defeat" and enemy mob goes "oh yea? I still have my final penultimate, super secret transformation you have yet to see!"
And the main characteer will obviously sit back and let this asswipe finish transforming so he can struggle ANOTHER chapter before defeating him.
The cherry on the top? MC will still refuse to kill him, and send him to jail because he is a mother fucking saint. And this mob will break out of jail for the N-th time just to reuse enemy fodder and come back with "Surprise motherfucker I escaped jail, never thought I could?"
It's batman and joker. Except much worse.