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.
Thank you for making me realize that.
شكراً لك على لفتِ انتباهي لهذا الأمر
Danke, dass du mir zugehört hast.
Gracias por hacérmelo ver.
Gracias por hacérmelo ver.
Merci de m’en avoir fait
prendre conscience.
Grazie per avermene fatto rendere conto.
Obrigado por me fazer perceber isso.
Спасибо, что помог осознать это.