Harlequin himself called them the Enemy (in Harlequin's back). So we can add that to the list of monikers. Usually, I think of that sort of thing as working best as a looming problem, where if we don't deal with the little related issues now, it'll get out of control really quickly. If they're already launching a full-scale invasion now, how will anyone be able to stop it?
Still, let's just wait and see how this turns out... (The revealings, I mean, not the hypothetical invasion itself)