Mutant Turtles: Superman Legend(1996)

Mutant Turtles: Superman Legend is an animated series that pits the Teenage Mutant Ninja Turtles against their most powerful adversaries yet. When the turtles obtain Mutastones from Crys-Mu, a spirit of light, they gain the ability to transform into Super Turtles for three minutes at a time. But Shredder and his henchmen Bebop and Rocksteady discover the Dark Mutastone, which grants them their own devastating upgrades: Devil Shredder, Supermutant Bebop, and Supermutant Rocksteady. The conflict escalates when the four turtles unlock their ultimate trump card—the ability to merge into a single unstoppable warrior form called Turtle Saint. High-stakes battles and supernatural power-ups define this action-packed adventure.