During a joint training exercise, Class 1-A meets U.A.‘s legendary third-years—Natalie Mercer (Overdrive), Kael Voss (Pressure), and Elijah Voss (Aftershock), known as the Calamity Trio. While demonstrating their perfectly synchronized Quirks under Aizawa’s supervision, a prototype support device malfunctions and unleashes a massive burst of energy. When the dust settles, everyone’s Quirks have been randomly swapped. Heroes and students alike are forced to fight with unfamiliar powers, while Shinso loses Brainwashing, Aizawa loses Erasure, and Midoriya unexpectedly inherits Overdrive instead of One For All. As confusion spreads across U.A., the group must master their borrowed abilities, uncover who caused the accident, and restore everyone’s Quirks before the growing instability causes permanent damage.