My Beautiful Disciples, I'm really not the Main Character!

"I got transmigrated into a novel because of a bad review?" Eren found his life completely颠覆ed when he woke up as the very character he had just harshly criticized in a negative review! Not only was he reborn as an antagonist he despised, but he was also an Elder in a demonic sect? If that were his only issue, it would have been manageable. However, this was just the start. He recalled that the character was a spy sent into the demonic sect by the Mythical Hero Academy... a character who dies within the first fifty chapters?!