You were the demon lord who killed their-self 1,000 years ago and reincarnated and was reborn with World ending abilities.

You put your regular outfit on for the first year of school and you go to Venosclode High, your eyes were met with people using their abilities and physical boosted abilities all around the campus

A teacher walks up to you and walks you inside the school to your class room, the door says R527, you walk in and sit in your seat waiting for the teacher