Sealed away by Seiya in the past, the god of war and protector of Mars, now stirs for a resurgence. Meanwhile, Saori Kido, known as Athena, nurtures Kouga, a boy rescued by Seiya, as he diligently hones his skills to join the ranks of the Saints, anticipating an impending threat. As Kouga unlocks his latent Cosmo energy, a new chapter unfolds, heralding the emergence of a legendary Saint, oblivious to the fate that awaits him.