The entrance exam bots had deactivation switches for stealth heroes. Her light refraction ability is pretty strong, I wouldn't be surprised if later in life she learned to focus it into a beam lol Also, her quirk counts as a mutation type, so it can't be turned off. Unless... Well, spoilers.
Being invisible during battle is just bad. You could be accidently smasheeeed by teammates (even Todoroki mentioned it after USJ incident). Also she should be blind because light runs through her eyes. Mirio has this problem, so light moves through him, so he should be partially invisible with quirk
I don't like Toru, because she is a big plothole. She is just a regular girl but with invisibility. How did she has more points than Deku on quirk test? Deku at least throwed a ball and her results should be, well, regular. Useless in battles, not only because lack of strengh or equipment.
Honestly there's some surprisingly good hentai of her, sometimes stuff is sexier with clothes on. But form my understanding wouldn't it just be like a Violet Parr situatio where eventually they'll have a hero technician create a suit that matches with her power similar to how Mt. Lady's clothes grow
Tokyo winter might be cold for Brazilian standards but it is not as cold for temperate climate standards. It rarely snows and they have heating indoors. With some training one could go naked at that time of the year, in fact in new year some people beat mochi almost naked in festivals.
Honestly.. shes pretty perfect for the City life. Cant be seen, she can learn Martial Arts to defeat most Enemies and her scouting ability is unmatched. Outside the City.. well she sucks :P
Something the manga never explored is that anything placed inside Toru would not be seen. She could have a micro radio placed in her mouth or hide a weapon in her other *places*. Now that's fans service ;)
