A Attack-type booster that's going to be revealed in the June 2017 issue of CoroCoro Comic (Which is gonna be released on May 15, 2017) and will finally be released in June 2017.

Leak: http://corocoro.tv/next/index.html

OK, but no, we are not that certain yet that it will be B-85... Plus, I already made a topic for B-85 anyway.