The Alter Bearer Of Realms.

In the Union world, 90% sentients have obtained powers of chakra, sacred gear, quirk, ninja art, etc. Yet, those who were weak is looked down upon by the egos of superior beings. One of the weak humans is a Union Academy student and you can clearly see how well he's treated, similar to many schools around the world these past years. He thought his dream is already crushed and is going to die by these corrupted students. However, time has seem to slow down when a voice calls to him from the small crystals around his wrist. It told him that his life wasn't over yet and can start over to multiple realms if he enters the strange portal outside of the Academy's entrance. Making a decision, he goes to pack up everything and jumps into the unknown portal. One where he'll find new friends, love interests, action battles, mysteries, and danger looming across the Realms, including the ones back in his old world.

(Note: I feel sad that there's some rare stories of Star Ocean, .Hack//Sign, Tales Of, and Elsword. So then I thought hey, why not make one with those ones crossing over with Union Academy?)