Deku has 8 persons inside him, i think he can mitigate some of its effects
Yeah.
Its an insta win if he touches(presumably with his hands).
So the goal is going to be avoiding getting touched.
its also a strong quirk because it has area of effect in places that aren't being touched(IE, her removing atmosphere from a place in front of her).
Its also a quirk that relies on verbal command.
So the easiest way to defeat it is to break the jaw, or silence them.
But I could see someone like AFO doing nasty shit with this ability. I really want him to use it to make Deku's live hell.
Also, he could probably easily infilitrate UA using a quirk this powerful.