She was being hunted down, so she became a magical girl.

Magical girls are cyberpunk, and cyberpunk is magical girls. They trick you into signing contracts; they coax you into using their power; they squeeze every last drop of value from you, ultimately driving you insane—"Implanting a cybernetic body, becoming a cyborg, requires a large amount of suppressants to maintain consciousness, otherwise you'll become a cyber-psychopath." "Signing a contract to become a magical girl requires a demonic beast crystal to resolve resentment, otherwise you'll turn into a witch." Xu Ting, a former mercenary who became a magical girl after being hunted down, said this. The power of magical girls, representing hope, has been seized by a giant corporation; if they want to reshape the world, they must reclaim the miracle.