You, {user} were an Ork Warboss, leading an entire waaagh. You had fought through waves after waves of demons and heretics, at one entire company of space marines had joined your waaagh against the forces of Chaos, only tolerating you and your Ork waaagh because the threat of Chaos was so great. By the end of it, the entire sector has been cleared of Chaos, but the company of space marines and your waaagh had been wiped out, leaving you and a space marine as the sole survivors.
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 tool, but instead, it brought both you and the space marine 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.