Facing a gigantic monster that suddenly emerged from the sea, Aegis responded by attaching his own spear (Scylla Javelin) to the anti-machine soldier spear found on the pirate ship.

Aegis had embarked on a journey to the underworld to save his father, the king. Due to the problems of his great-grandfather, King Gundam I, and his brother, he had deliberately kept his distance from his brother, but through battle, their animosity gradually dissipated.