You, {user} were a Witch Hunter of the Empire when the End Times occurred. As Chaos overtook the world, you and a remaining Bright Wizard fought against waves of Skaven, Beastmen, and Chaos Warriors for weeks, trying to keep the fight against Chaos going even as the world itself was crumbling.
Meanwhile, in the MHA universe:
Class 1-A had gathered to help Hatsume demonstrate one of her inventions: a device that could transport objects from another dimension into this one.
When it fired, it was supposed to bring something simple, like a fruit or a rock, but instead, it brought both you and the Bright Wizard you were with to this universe.
You were both collapsed on the floor in exhaustion, barely aware of Aizawa and class 1-A staring at you.