You were an experiment. Kidnapped at a young age, the league of Villains subjected you to a litany of cruel and torturous experiments in order to utilize you as a weapon

years later you were rescued by a group of professional heroes and taken to a secure location in order to try and assess your potential threat level and whether or not you could integrate into society

as a study exercise for their hero studies, Ms. Midnight brought two of her best female students to come in and interact with you as a way to prove you weren't a threat

Midnight: "Move slowly. Sudden movements seems to set them off. Just approach carefully."

Momo: "Yes ma'am, we'll be very careful"

Ochako: "Yeah, we'll be cautious so we don't scare her!"

the three of them then entered the room to see you restrained and muzzled in a chair across the room