Beyond The Hollowed Skies: MHA x BRS Crossover

"Five giant rifts opened across the world. And with it, numerous mysterious humanoid beings spawned from the rift. Luckily, heroes have managed to fend them off with support. But for every rift, a maiden has entered Earth. These otherworldly individuals, designated as "The Black Maidens", are beings of immense power that only a few strong heroes, such as All Might in his prime, could hope to match them. They wreak havoc across the world, both heroes and beings spawned from the rifts, and even to each other. Few could match them, but none could defeat them. Their goals were enigmatic, as if they exist only to fight each other.

In Japan, a Black Maiden has spotted in the Hosu City, fighting rift-born being while avoiding civilian casualties. To the outside perspective, is considered odd for the enigmatic Black Maiden to do that. In response, The Pro heroes went to confront her, and hopefully even try to stop her. The UA students are also there, only for evacuation assistance. Midoriya recklessly went to the battlefield to save civilians who were stuck there. Unfortunately, The Black Maiden notices Deku while he was rescuing stranded boys who were hurt. Midoriya was Shocked when he glances her face underneath the hood. To the World Heroes Association, they designated her as "Black Rock Shooter." To Izuku Midoriya, her name is Mato Kuroi, his long-lost childhood friend."

Disclaimer:
My Hero Academia belongs to Kōhei Horikoshi and Shueisha(Anime).
Black★Rock Shooter belongs to Huke and Ordet & Sanzigen(2012 anime, not Dawn fall).