The Otomes face off against Nagi and the power of the Harmonium, and Arika comes into conflict with Nina in a final battle, having unlocked the true power of the Blue Sky Sapphire. Arika tells Nina that it is not too late to make up for her mistakes, and manages to defeat her even as the Harmonium takes possession of her, destroying the Ultimate Black Diamond. Some time later, Mashiro addresses her people, and Sergay awakens from his coma under Nina's care.