Return of the Absolute Champion

Liam Hill, the Absolute Champion, is betrayed by his comrades and sealed away with the Calamity Demon after losing his powers. For centuries, the demon has returned every 300 years to threaten humanity, and Liam once faced it with the power of 108 as a member of the Hundred Man Squad, an organization of chosen reincarnated beings. After 1,200 years, a mysterious voice guides Liam into the body of a bullied student at a magic school. The world now remembers him as a rare villain, while reincarnated traitors secretly operate within the school. Stripped of his former power and starting from the bottom, Liam begins a quest for revenge as an anti-hero.