My Hero Academia Sets Up Izuku's Deadliest Power Yet

My Hero Academia is setting the stage for Izuku Midoriya's most dangerous One For All power yet with the newest chapter of the series! The Final Act of Kohei Horikoshi's original manga series has tested Izuku in a ton of ways he never could have seen coming when he started his stint in U.A. High School just a year ago. One For All has placed a huge burden on his shoulders, and now he must master it all in a matter of moments before he comes face to face with Tomura Shigaraki's full All For One power.  

Izuku had only unlocked the final two powers belonging two the previously mysterious second and third vestiges, and as he continues to master his abilities as much as possible, there are other variables making matters even tougher as each of those skills is much stronger than when the original users had it. All of this has combined to learning as much as he can on the fly, but there's still one major quirk within One For All that he has yet to even use, let alone master, because it's too unique of a power that it can only be a last resort. 

(Photo: Shueisha)

Chapter 349 of My Hero Academia sees Izuku flying over the ocean and he's trying to figure out how to use his abilities to get him to Shigaraki as soon as possible. The second user reaches out to him to try to get him to calm down as reassess things, and figures out that Izuku tried to use his quirk. He reveals that he told Izuku to avoid this quirk as it's meant to be a last resort. He explains that as One For All got stronger, all of their respective quirks got stronger as a result. But the second's in particular changed into something unique. 

He warns that it's not a power that can be wielded in the way he was able to in the past, and tries to talk Izuku out of his current desperation. Now that raises the question of what this ability could be. Not only do we not know what his original meta ability was, there's no way to try and guess to see what it was morphed into. He mentions Izuku used it, but it's something he figures out after he realizes Izuku was going to try and force his body (and thus hurt himself) to move faster. So is it some kind of healing quirk? 

What do you think? What could this mysterious power be? When did Izuku try and fail to use this power? Let us know all of your thoughts about it in the comments! You can even reach out to me directly about all things animated and other cool stuff @Valdezology on Twitter!