This is a series based after the final battle was concluded, after the fall of the King and the rise of the sun.
Six months after the last battle, the Crown City of Insomnia aims to revive themselves from the consequences of war and invasion. This involves repairing the city's infrastructure and reestablishing the government power, in which Gladiolus wants nothing to do with it.
A bitter clash of differences between him and Ignis had resulted in Gladio's complete separation of the new Civil Order that Ignis has created, which in turn, meant Gladio's removal from the personnel overseeing any future development of Insomnia.
Gladio walks the roads of Eos, serving the community that he believed the Crown City had, again, neglected. However, doing so made appear like a purposeless vessel, yearning for something he had in the past; a meaningful contribution to something...or someone.
After a surprise reconciliation with Cid, Gladio learns of a new evil that aims to plague Eos from the depths of Niflhiem. And in his efforts to defeat it alone, he finds himself in the presence of a corps that is exactly what he is yearning for.