I Reincarnated as a Side Character, So I Became the Villain (ATG)

He died. No glory, no epic battle, no final redemption. Just poof, the end. But the story didn’t end there. When he opened his eyes again, Ren Zu found himself in a world where profound cultivators split the sky, the earth… and even the stars. And the worst part? He wasn’t anyone important. Just a background character — the biological son of a prodigious cultivator who died before the story even began. The protagonist? The one who shines, conquers everything, and is loved by all? He was adopted by Ren Zu’s original family. And Ren Zu? He was thrown into the protagonist’s birth family. Their roles had been reversed. And as if that wasn’t enough, the protagonist even stole his wife… Now, Ren Zu is trapped in the role of the emotionally useful NPC — the kind who’s destined to die early, just to serve as a trigger for the hero’s rise. Spoiler: He’s not going to accept that. If the world wants to erase him, then the world will burn with him. If fate gave him the role of a disposable side character… …then he’ll become the villain who defies even the heavens. — Description from novelcodex.org