Despite Minna's objection, Mio heads inside the Yamato and gives the Neuroi Dynamo her remaining magic power which kick-starts the engine. Mio is then able to fire the main cannon, destroying the Neuroi nest. It is revealed however that the dome was mearly a shield concealing the hive's massive core, which Mio becomes absorbed into. Not giving up, Yoshika, with backup from the other Witches, retrieves the Reppumaru and is able to perform the True Reppuzan which only Fuso Witches are capable of performing. This destroys the giant Neuroi core at the cost of Yoshika's remaining magical power, freeing Mio in the process. With Venezia finally free from the Neuroi, the 501st Strike Witches are once again formally disbanded; and Yoshika begins her medical career. The final shot depicts Yoshika's special Striker Unit having washed up on a beach alongside the Reppumaru, the shadow of an unknown individual then appears to find them, setting the scene for the film. (thetvdb.com)