Fou is the guardian deity of the Black Order's Asia Branch, sealed by Bak's great-grandfather. Though not human, she frequently assumes a humanoid form to communicate with others. After Tyki Mikk's attack, Fou discovered Allen's body and brought him to the Asia Branch headquarters. She has a "tough-love" approach, especially towards Allen. While training him to reactivate his Innocence, she would mercilessly attack him, hoping he would activate his left arm. When Allen felt down, she appeared as someone else, like Lou Fa, allowing her to show her softer side without revealing her true identity.
Despite teasing Bak, Fou shares a strong bond with him. She can alter her form, transforming her hands into axe-like weapons or mimicking someone's appearance. Additionally, she can communicate telepathically with others. The Asia Branch Headquarters is safeguarded by a powerful barrier created by Fou, who acts as its "entrance." Beneath her tough exterior, Fou is deeply caring and willing to sacrifice herself for those she loves. She once took Allen's form to confront a Level 3 Akuma, buying time for the real Allen to escape. Before the fight, she whispered, "Bye bye, Bak." Though severely injured in the battle, she was shown to be recovering after Allen defeated the Akuma.
