After the intense Thrihexia battle, Issei Hyoudou, the once-celebrated pawn of the Gremory clan and the hero who fought for peace, finds himself cast aside by those he fought to protect. Betrayed by every being in the supernatural world, his sacred gear, the Boosted Gear, is seized and given to his brother, who is hailed as the new hope. Draig, the Red Dragon Emperor, finally feels relief, free from Issei's perceived weakness.
As the world turns its back, Issei awakens to a past shrouded in pain and neglect. He remembers his childhood, tormented by his family's disdain, bullied and ridiculed in school for his perceived uselessness, and shunned by the supernatural community for being a "pervert" and "weakling." Yet, deep within him, a power older than his time stirs-Sukuna, the King of Curses, reincarnated into his very being, seeking revenge.
Fueled by memories of betrayal and the burning desire to prove his worth, Issei embraces his new identity. Alongside his loyal harem. Issei becomes a formidable force of vengeance and power. No longer the hero, he will become the villain the world fears, reclaiming what was stolen and reshaping fate to make them all pay.
Issei lived a happy childhood, he had a loving mother and father and that's all he needed. Until one night men with black bird wings came and killed his parents. Fueled with rage, Issei awakens the boosted gear and slaughters the men that attacked his family. Unfortunately It was not enough and he was left broken and alone. It was not until a red haired Satan came and rescued the child and took him back to the underworld. Watch Issei make his mark as he becomes the most powerful red dragon emperor ever.