Fosschild is a gifted hacker, originally living on the streets of Metacity, eventually becoming Techno-Mage's student.
Fosschild upon seeing OpenBlade for the first time
Techno-Mage first encounters Fosschild in Metacity. The child is ecstatic upon seeing the mage carries the mythical OpenBlade. After the short encounter, where the mage recognizes the child's potential, she rescues it from homeless life and brings it to her home and begins tutoring it as her own student, much like Puffy once did to her.
Fosschild later appears in its own spinoff series Fosschild.