@WhimsiCat i think it was rather because of him dying, like, being relieved of his "mortal" shell and returning to the system (or something along the lines). right before that he looks shocked and scared because he found out who/whatever the MC is
But if our Novel Protagonist doesn't regress anymore, because our dear MC stops it everytime, doesn't that make the Regression abilty (one reason he got so OP?) 'useless' and also makes him not OP like in the Novel he read ?