The fake extra

Liam was a high schooler, who was nothing but your typical person. He had just read the ending of his favorite novel and was pretty disappointed but the next morning he wakes up as a character who was only ever mentioned in one or two chapters in the whole novel. As an active reader, he knew the fate of the world he was currently in and he was determined to survive even if it meant changing the novel's original plot. Using the knowledge he has, Liam was going to become one of the strongest characters aiming to kill the MC so that the world doesn't suffer its destined fate.