My Hero Academia's latest arc has seen a greater focus on the villains of the series as Shigaraki and the few remaining members of the League of Villains are currently embroiled in a fight with the new villainous faction, the Meta Liberation Army. With this greater focus, fans are beginning to see much more of the villains' personalities, and are getting answers to many of their burning questions.
The latest few chapters have been slowly growing Twice's power as he battles against his psychological scars, and Chapter 230 of the series helpfully explains exactly how his Double quirk works right before unleashing his biggest attack yet.
As the chapter begins, Twice explains the how his Quirk is limited. Although he can "turn one thing into two," Twice can only duplicate two different things at once. Along with this, the doubles will be more fragile than the original. Coupled with this, Twice's second duplicate will always be weaker than the first duplicate. He also explains that he can't duplicate another object until the first duplicate vanishes.
There are other limitations to his quirk as it's revealed that Shigaraki tried to have Twice duplicate the Hassakai Family's Quirk killing bullets but Twice couldn't make it work. His Quirk requires data and an image in his head, and without knowing what it is, he can't just make a double out of thin air. So luckily for the heroes, Shigaraki and the others couldn't produce more of the bullets.
Twice took these limitations pretty hard as he was apologetic for not being of help to his friends, but Chapter 230 sees a new kind of Twice as his ultimate attack multiples himself to a nutty degree as a wave of Twices soon come to save the other villains soon enough. So while his Double quirk has its limits, it seems he can multiply himself to a wild degree and still offer to multiply either Dabi or Mr. Compress, as he puts it, 20,000 times.
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 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. My Hero Academia is gearing up for an even bigger end of 2019 with a new film in theaters later this year too.