Anyone else see this thing as our first Legendary CAP? It has a 600 BST, so that means its either acts as an event Legendary or a Pseudo-Legendary, the latter of which would require two prevos and an immunity (which clearly we do not have). Therefore, since nothing else has anywhere near 600 BST without a gimmick, it's clear to me that this thing is at the very least exclusive to one-per-game.
I very much doubt it. This thing will most likely have egg moves, pretty much. Which rules out legendaries as an option. Besides, pseudo-legendaries are only defined by the 600 BST - the immunity is an inconsequential observation (as in, they are not an official Nintendo class of Pokemon, they just happen to have a recurring BST - I would be more than willing to bet that the immunity is coincidence, and no more than them all being able to surpass 400 Attack (until Garchomp) or all having attacking stats of 130 or higher (until Hydreigon...)).
More to the point, FLUFFY MOTH PREVOS EEEEH - well, anyway. Ahem.
Nice to see that this place is getting some activity! I might actually share some of my own flavour ideas, since I can't submit a movepool this time around...
To me, I enjoy movepool flavour where all the flavour moves share some sort of archetypal significance. Most notably, since this Pokemon shares the sort of divine theme with Arceus, a good place to start looking for movepool flavour is Arceus's level-up movepool. I like the idea of Punishment, Cosmic Power, Natural Gift, Hyper Voice, and Gravity on this CAP. Judgement would also be nice, but alas that it is legendary-exclusive.
Another nice group of moves in flavour terms would be the all-stat raisers, namely Silver Wind, Ancientpower, and Ominous Wind. The former two are fairly obvious in flavour terms; Ominous Wind is a little harder to justify given its association with dark and evil and what not, but it might be a nice touch or another part of Aurumoth's character. Speaking of wind, that's another direction to go in, with such moves as Air Cutter, Razor Wind, Icy Wind, and Gust being nice additions along that theme. Unfortunately I almost certainly will not be allowing Hurricane, so that doesn't work.
These are all the ideas I have off the top of my head; it would be nice if everyone could pool their flavour ideas here to give movepool creators their own ideas, or at least a starting point.