My Hero Academia's Joint Training arc has been steadily building to a big climax as the focus of the arc has seen more of Class 1-A and 1-B's come into their own, and the latest chapter saw the build up one of its big additions, Shinso.
Shinso has been thrown into the training exercise in hopes of joining the hero course in full, but now that he's helped Uraraka save Midoriya from his berserk quirk, there's no doubt he'll be a bigger part of the series from now on.
In Chapter 212 of the series, Midoriya's One For All has unleashed a scary new power that he can't control, and Uraraka has jumped into the eye of it in an attempt to calm Midoriya down and stop his rampaging quirk. She calls out to Shinso, and tells him to brainwash Midoriya in order to stop the frenzy.
He's stunned for a moment, because he has no idea what to say to Midoriya in order to brainwash him (as his quirk needs someone to respond to him in order to be effected). He remembers when he lost to Midoriya during the Sports Festival, and it's here that fans see a different side of him. He remarks that he was actually to be a part of the joint training exercise between the two hero classes because he wanted a chance to show Midoriya how much he's changed since their first bout.
He vows to fight Midoriya again, but he's looking forward to it as a friendly rival. Shinso once again reaffirms that he will be a great hero, and use his quirk to help people. With his resolve affirmed once more, Shinso yells out to Midoriya "Let's fight!" and Midoriya struggles to respond with "okay." With this, Shinso successfully brainwashes Midoriya and saves him from further hurting himself and everyone else.
With this big hero declaration, Shinso puts himself on a clear path to becoming a strong pro hero, which is a much different path fans initially saw him on in his first appearance. Hopefully, now that he's free of much of that previous negativity, becoming a hero will come much easier.
My Hero Academia was created by Kohei Horikoshi and has been running in Shueisha's Weekly Shonen Jump since July 2014. The story follows Izuku Midoriya, who lives in a world where everyone has super powers, even though he was born without them. Dreaming to become a superhero anyway, he's eventually scouted by the world's best hero All Might and enrolls in a school for professional heroes. The series has been licensed by Viz Media for an English language release since 2015.