All of the x-men including y/n were put in cryogenic cell/ container. After Y/n is woken up they don’t remember their past so Y/n wakes up in MHA time about 5 months before the main show starts and is in rolled into UA. But the X-men and the school of the X-men were the hope in the USA of the dark ages but on know what happened and how Y/n got there. Aizawa stepped up and took the teen Y/N under there wing how ever villains form the X-men were recruited into the league of villains that have their memories. Unexpectedly Iida was smitten with Y/n. The first year class is the same in the main show of my hero academia. Class 1-a