Mihaera

A beanie hides most of Mihaera's long white hair. She is young, her eyes are turquoise, and her clothing runs to a plain jacket worn over a shirt, chosen so she vanishes into a crowd of displaced civilians.

She treats the assignment as work. Like the rest of the infiltrators she stays composed while playing her part, and she accepts her master's instructions without argument, calculating that obedience buys her a place in whatever world he intends to build.

All For One planted five spies on campus, Mihaera among them, each passing as a refugee taking shelter at the school. Orders arrived through Tajima: stir resentment among the evacuees until the pressure pushed Izuku Midoriya out. The scheme never got its chance, because Izuku and Class 1-A announced their departure anyway, and the spies relayed that news back to their master.

Once the Final War opened, the group answered to Skeptic instead. Mihaera and Tajima waited among the evacuees while he broke into the school's systems and crippled the evacuation blocks standing between the campus and Shiketsu High School. One block's foundation was permanently disabled, forcing the refugees inside out into the open, but the operation ended there. Gunhead, Itsuka Kendo, and Tetsutetsu Tetsutetsu rounded the infiltrators up, and one of Itsuka's enlarged palms pinned Mihaera and an elderly fellow spy to a wall before she could trigger the explosive planted beside her.

Whether that bomb came from a Quirk is never established, though her proximity to it suggests some familiarity with the work. Her fate after her master's death goes unrecorded, with continued custody the likely answer.