Three years ago, Serizawa was troubled with about his psychic powers. One day, he was visited by the boss, Suzuki Toichiro. Serizawa ends up trusting him since he's the first person to understand what he's going through. But Mob then brings up the fact that Serizawa is being used and tells him, "I'll be your friend." Hearing Mob say that, Serizawa... 

Meanwhile, after defeating Sho, the boss starts gathering up the energy he was sharing with his followers and turns into an energy monster.
The powers they're using
like they're going out of fashion
...القوّة التي يملكونها
Die Kraft, die sie so
willkürlich einsetzen …
El poder que usan como si fuera suyo
El poder que usan como si fuera suyo
Ils puisaient d’eux-mêmes
dans une source de pouvoirs
I poteri che hanno usato...
O poder que eles possuem...
Сила, которую они считали своей,