Primals, Eikons and something I still don't understand

[Jandor]

Wth regards to Odin: Sephirot's and Sophia's thralls needed to be killed like any Primal thralls. Presumably, without the thralls, once defeated, the Fiend and Goddess were gone for good. Odin seems capable of existing without any active worshippers besides the thrall on Sleipnir's back, and without any more belief than a vague rumor of a demonic horseman in the Shroud. Even when Odin is defeated and the thrall is killed...how does Odin survive until the opportunity to claim a new thrall presents itself? Does it have to do with the true form of Odin, the Zantetsuken blade, being an actual physical object? How does only one person's forced worship give Odin the immense power he has?

I don't think Primals need prayer to stick around after manifesting. It seems to keep them from dissipating if no aether is around, for example with Bahamut and his thousands of sleeping dragons trapped in Dalamud, but so long as there is aether in the surrounding land to drain I think they're pretty much self sustaining after the summoning.

Edit: Bahamuts probably not the best example. He was trapped in a giant space solar panel for the Allagans, probably plenty of aether or equivalent power source available in that. Still, the Warring Triad trapped way up in the sky don't seem to have much in the way of external aether sources. They might make a better example? Not overly familiar with them tbh.

Anyway, my point is, Odin doesn't need thralls to keep him around and I don't think this is unique to him. I think either aether or prayer can keep a primal going, but draining aether for them is like breathing for us, you can't really not do it.