I'm still curious as to how Zenos would be a major threat without the backing of the Empire unless he intends to perhaps rally some support by spreading the knowledge of Hydaelyn and Zodiark, because I can imagine some Garleans might not be too keen on the idea of their lives being somewhat governed by some manner of super primal.

He's not exactly what you could call a world-threatening menace on his own, but give him a Garlean legion or two packing the latest tech and then you have a problem. I'm especially concerned as to how that tease about Tartarus at the end of the Ivalice questline is going to play into the bigger picture because a weapon, quote "with the power to tunnel to the very heart of the star" seems like something he'd be very much interested in.