The Springlocked Academia

"He was a prodigy born centuries before the first glowing baby ever cried. He built a masterpiece of engineering, only for it to become his tomb."
In the pre-Quirk era, 13-year-old mechanical prodigy Izuku Midoriya built a homemade Spring-Bonnie suit, only for a sudden accident to trigger a fatal springlock failure. Locked away in the basement of a crumbling stadium, he was forgotten by time.
Three hundred and seventy-seven years later, Izuku wakes up.
Trapped inside a seven-foot-tall, decaying animatronic suit, Izuku is now Springtrap-an immortal, undead corpse in constant physical agony. Waking up in the year 2400, he finds a world filled with heroes, villains, and superpowered Quirks. Guided by Principal Nezu, Izuku enrolls in Class 1-A at U.A. High to prove that despite his terrifying appearance and rotting shell, his heart is still that of a true hero.