Betrayed for Nothing then Reincarnated with a System
Nix was an average teenage noble excited to attend the academy with the love of his life. Until it was revealed that, he was part of a prophecy that needed his beloved, the chosen hero, to kill him to prevent the return of the demon king. He couldn't believe it until he was falling into an endless pit while watching the love of his life crying after she had just stabbed him.
However, while he was plummeting to his death. A quiet voice sounded in the sacrificial hall.
"Huh, I guess she was right. They would kill their love over a piece of paper. Well, the bet's concluded, the demon king will definitely return...Farking idiots."
*The Cover Isn't Mine. Credits to the author, just pm me if you want to take it down.