My Hero Academia: Who is Oboro Shirakumo?

gamerant.com:

The sixth season of My Hero Academia is upon us, and based on the original manga, this next season will focus heavily on the Paranormal Liberation War arc. There will be a lot of mayhem, confusion, and revelation happening in that arc. Many fans even considered it to be a major turning point for the series. Things will not be the same after this all-out war. One of the revelations that have already been teased in the fifth season is regarding one particular name, Oboro Shirakumo.

Not many people know or even recognize this name among the pro heroes, but for those who do, this name means the whole world to them. Not only that, but Oboro Shirakumo also holds a highly crucial key regarding one of AFO's most important assets and will greatly affect the events in the sixth season. So who is Oboro Shirakumo? There's not much information regarding Oboro Shirakumo in the main series of My Hero Academia. However, there's a spin-off manga titled My Hero Academia: Vigilantes where he will make an extensive appearance during Eraser Head's flashback.

My Hero Academia: What to Expect From Season 6 (According to the Manga)

Oboro Shirakumo was a former student of the U.A during the time when most current pro heroes, such as Eraser Head and Midnight, were also still students. He was a loud and energetic teenager who often took the role of the joker in the class and always kept a smile on his face and an optimistic outlook on his mind.

Shirakumo's quirk was called “Cloud”, and his hero name was Loud Cloud. As the name suggests, his quirk allowed Shirakumo to create a cloud-like substance. Shirakumo can put objects within and on top of his cloud. Furthermore, similar to the «Kintoun» from Dragon Ball, Shirakumo's cloud can also hover and fly.