The nation of Madeza supposedly has deities that protect their borders and respond to their ritual magics. It's either that, or the ritual magic is independently powerful, because they don't get natural disasters and no one's ever successfully attacked them. The ley makes warfare difficult, but they have nearby neighbors who could present a threat, and they're not the only nation on their reality-island.
The going theory for the creation of the realm where I'm from is that there's a single deity that created all the worlds, possibly with sub-creators for some of them. There's no actual proof of this, though, other than some observed similarities between worlds - which could be down to other factors, like split timelines, convergent evolution, multiple creators copying either each other or a single original template, etc. We have a tremendous variety of religions, many which claim their gods created the realm, again without proof.
There's no evidence that the realm was even made, rather than evolving naturally from bits stolen from other worlds, or that it has any native gods at all - Madeza has good enough records to show that they worshiped the same gods in their previous world, and we suspect that any other gods might have been brought with the worshipers, if they even exist. (There's shaky proof of powerful magic-granting beings in other worlds - some people have their divinely-granted magic stop working when they appear in the realm)
There are spirits - a pretty broad class of being - who some people worship, and who can sometimes grant boons or cast curses, and a few of which can create their own folded terrain or even pocket worlds, but I think they're overall on a lower level than the other Powers I've heard described. I'm friends with a cat-spirit, and I've spoken to a rather powerful and old desert-spirit who likes to work with the university's history department. There's spirits of most major landscape features - especially water features - and plant and animal spirits, plus a few smaller categories.