[X] Hoygor, an odd spirit. One unintentionally summoned by the Astromancers of Cathay, one who was influenced by them and learned
Azyr from them and integrated it into his nature.
The foxes will be popping up near Cathay, so this gives us an in with them. Also, 'odd' characters are always interesting, considering this one is considered odd by literal spirits of the warp, this promises to give us esoteric options. Or as esoteric as you get when you are talking about warp-borne entities with a (presumably) significantly high ground from a materium's mortal perspective.
Furthermore it synergizes with our Ulgu specialist, not only shall the foxes be cunning, but also unpredictably so.
[X] Qasarat, a spirit of that which is hot and bright and furious and lusty and loving and joyful and a thousand other things within nature, from animal to beast and back again. Many times he has been called upon to consecrate a wedding for mortals, particularly by the Kislevites. He is marked by
Aqshy.
Fire is a common feature of virtually every civilization on the planet, I am hopeful this will grant as a bonus to understanding the mortals' perspective then, through making that fire which they share something the foxes intimately know.
As such, I reckon this one will give us a good window into the feelings of mortals, their outlook, the way they see the world, etc. Which I believe to be vital for a race of incarnated spirits, they shall be otherworldly yes, but that does not mean there shouldn't be the warmth of the living in their gaze, or that they should struggle to comprehend the ways of 'warmbloods' as the First Children of the Old Ones do.
This option makes sure we have/accomplish that, and, looking at the bit about 'a thousand other things within nature', so much more.
It's not only 'I cast fireball', is what I'm getting at, though yes, there will be some of that too, and no, it won't set the jungle on fire, as others have said. Jungles are too humid for that, and in fact, seeing as the foxes don't wear clothes, it might be the way to keep them warm in the cold, wet nights.
[X] Liad, a singer often summoned by the Maiden to provide art and glory for her servants, and has been sent to do so in return for companionship. He is marked by
Hysh.
Is this Maiden the Everqueen? Aside from that boon, Hysh will be very useful against all the Deamons in pursuit, and in a less martial tone, I really want to see an artist that wields Hysh. It can also have positive effects in the way mortals view us, because surely an entity that wields the White Wind cannot be tainted by dharr?
*Looks at vampires nervously*
Even then, cleaning up corruption and ruining the Horned Vermin's day by making warpstone disintegrate can only be a good thing.
And I want artistic foxes, dangit! 
Maybe this will be a path to developing clothes and such too? At first for fashion, then for function.
I would pick Derehan, our Ghur specialist too, both for the synergy and the experience, however, doing so would lock Hoygor our Azyr specialist further out of the race. So I'm not picking them because we're already foxes, and I assume we'll have reasonably deep Ghur knowledge by default, and picking Derehan would mean specialization on that front, while I, personally, prefer the possible synergies between Ulgu and Azyr, plus the connections with Cathay.
Still, shape-shifting is, frankly,
quite based imo. So I'm not totally against that winning either.
