So from the looks of it so far, the lore will just be encountering each Artmage member's future descendants in fucked up alternative futures.
>Medius already saw the future in Theorealize
>-Lineage- implies a familial connection between Graflare and Drastia/Drastrius
Got to assume the eventual Synchro/Link will go to Litera and Finmel and the whole lore will be stopping these alternative futures from happening, maybe with a corruption mini-arc of Medius turning evil temporarily from absorbing and using the powers of the alternative future Power Patrons so frequently.
Something something power of friendship, each Artmage uses their alternative future powers but in a good way culminating in a new Xyz, Synchro and Link for their respective Artmage to counter the new fucked up Medius Ritual or something.
Medius breaks free of the corruption, fights the ultimate Power Patron or some shit. Then close the curtains on either a good end or a cliffhanger where a new Power Patron is reborn or some shit