This story is a sequel to Convergence
"Living in the pastel pony apocalypse has always been strange.
Having a godlike knight, an avatar of vengeance and the latent magic of Britain, though, that one was a bit of a curveball. The PHL, a brave resistance group founded by Ambassador Lyra Heartstrings, is bewildered but enthusiastic at the unexpected arrival of David Elliot, the Avatar of Albion. His entrance into the PHL's world, bringing his unique curative magic and the warriors and militant cults of his world, is a double edged sword, however - for his enemy, the corrupted Celestia now known as Empress Solamina, has her eye turned to these new worlds with the intent of conquest.
Faced with war on multiple fronts, a war unlike anything in their history, the peaceful 'Downtime' Equestria must prepare now to stand by its allies, or risk losing everything they have worked so hard to accomplish. Time... is running out."
Though I should point out here and now: This is not exactly a sequel to Convergence. More of a sidequel, really. Marking it as a sequel was just the easiest way to mark this as connected.