BoBoiBoy x BNHA crossover: When worlds collide [HIATUS UP UNTIL FURTHER NOTICE!]

(Takes place after the Retak'ka fight in Boboiboy movie 2)

This is it. His reign ends. Retak'ka, is now defeated. Boboiboy got his elementals back, who were happy to see their true master, not wanting to leave his side ever again. But when he trips and falls, Boboiboy's friends follow, a portal appears, transporting the Kokotaim geng to an unfamiliar place, or ... universe.
~~~
(This takes place in the USJ attack in My hero Academia)

Villains raided the USJ, where Class 1-A's lessons takes place. Iida already left to call for help. Students were scattered across the domed building, with villains attacking left and right. Izuku, Asui and Mineta were to begin forming a plan, when a portal appears, though not the same as one which separated the students. Five unknown figures come out, who dropped down below in the lake.

The trio rescues them, and that was the decision that changed their lives forever...

Boboiboy belongs to Monsta and My hero academia belongs to Kohei Horikoshi.
Plot line only belongs to me.
The first book so beginners mistakes might and will appear in the book.

Edit: This book will have a lot of OOC, especially the elements. I will try to be as accurate as possible, but I will be showing their behavior or actions based on my headcanons.