Isekai Kenja no Tensei Musou: Game no Chishiki de Isekai Saikyou

Synopsis:

In order to finish his novel, the protagonist, whose days are numbered, risks his own life as an author. a work that everyone has heard of and is extremely popular. After finishing the story, he eagerly awaited its publication, but his life unfortunately ended—— [Why am I being transformed into a mob character doomed to ruin??] He out of the blue got immigrated into the clever he composed. Additionally, he changed into Will, the underdog mob character from the beginning of the book. The character who is the eldest son of the noble family that will soon be destroyed is a character who has no talent for magic and whose future is bound to be miserable. It was the worst place to start, but he, the original author, didn't care about it. He is the author of the original work, so he knows everything about the quests and events, powerful magic and items hidden in plain sight, the strengths and weaknesses of the beasts, and even the secret of the world. Will will use his knowledge of the original work and strive to be the strongest person in the world to save himself. I will alter the future. That is the justification for why I have the information on the first work]. He will be an unparalleled character in this world when he uses the original work knowledge cheat to change the fate of a mob that even left the hero in awe.