SSS-Rank Slap Skills Turned Me Too OP

A man transmigrated as a side character in some lonely web novel that earn nothing more than some power stones and fake ahh.. reviews from the author's friend. He changes the fate of that side character, he refusing the offer of dark powers that the character was originally supposed to accept. After rejecting the dark power, the God of Fiction from the web novel departement appears and..... ***** [ Cringe probability ] : 99.99%