I think that I like where you're going with this. However, I think as well that you need to do some more work on the cultural end.

At the very least, cheat and base (for example) the frost giants on several different raiding civilizations, so you've got Mongol Frost Giants, Scythian Frost Giants, Gothic Frost Giants, and so on. Even better, however, go from first premises-- what is Ise like, what is frost giant physiology like, &c, and what sort of various cultures would come out of that? Emphasis on various, because monocultures are not your friend.

Here's the reason that you need to be intense with your worldbuilding: There are more or less two kinds of people who read spec fic. There are people who don't care about the world and just want to practice escapism, and maybe a generic world is actually a good thing because they like the formulaic stuff. Then there are people who, like myself, find the biggest draw in spec fic to be the new world, because if all they cared about was interesting stories and character development and so on, they could find that in To Kill a Mockingbird and The Lord of the Flies.

In essence, you've got people who don't care about generic material, and people who want something really interesting, well-thought out, well-developed.

You can't count on selling to the first group. This is important to keep in mind. You can make the most formulaic dribble possible, but friend, let me tell you, there are another ten thousand stories out there that are just as formulaic as that one. You can't stand out. If you become a spec fic success with a crappy world, then it's ultimately because you got lucky (or name branding, but that doesn't come from nowhere) and then the popularity fed on itself from there.

This means that the only kind of success you can count on is what comes out of an extraordinarily well-developed world. And this is the problem with, say, Wheel of Time or Game of Thrones.

First, Wheel of Time. I've talked to fans who raved about the series, and every one of them has admitted that the world is nothing new. If you've read fifty other fantasy novels, then you've already read this one. They recommend it on the basis of well-written characters, &c &c. But friend, I can get that in Mockingbird. If I were a Type 1 reader, who read for escapism, then maybe this would be enough for me anyhow, but again, you can't count on that. Wheel of Time got popular, but just as plausibly it could have gone another way.

You can't count on an underdeveloped world getting runaway success.

Game of Thrones has a similar problem. The way that the seasons work, that's kinda neat. The Others, and the fact that dragons both exist but were extinct for a good portion of time (usually doesn't happen in fantasy), are also respectably interesting. The problem here is that it doesn't take me very long to read over all of the interesting worldbuilding in Game of Thrones, and then I'm done. My biggest thing about spec fic is the world, and I will suffer through a bad plot or two-dimensional characters for an interesting world (hello, Lovecraft). If I can get the full experience of the world in a wiki binge then I'm not going to pay out my time to read twelve books.* If I want cray backstabbing and gritty crap going on in my story, then I'll just check out the historical novels section of my local Amazon webpage.

Contrast, however, with Discworld. A higher word count than Game of Thrones and Wheel of Time put together, but I'm still going to read every single book. Why? It's not just well-written, it's not just got a bunch of great characters, it's also got a world that I can't possibly thoroughly experience without reading the books. That world is so deep that to make a fully accurate map of that territory would be to walk the territory itself. It cannot be done with a wiki binge.

Heck, this is why I started reading Homestuck. I tried to do the wiki binge, and then I realized that I wasn't going to be able to get it like I wanted, unless I was willing to sacrifice my time to a work that was longer than frikkin' War and Peace.

So you need to build the hell out of your world. Metaphorically, anyway. If your world really does need a hell, then don't build that out of your world. Keep it in.

But the only way that you can be reasonably confident of success is if you can show the people something they ain't never seen before. Don't just make your frost giants raiders, and your cloud giants peaceful and mysterious. And don't just make them fantasy Mongols and fantasy Buddhists either. Take inspiration from 'em, sure, but do it like the world ain't ever seen it done before.

You're off to a good start here, friend. I look forward to seeing its future development.

This is why, by the way, the world becomes ever more important as the series gets longer. I might be more willing to read *Game of Thrones if there were just one book, and not a thousand of them, and each one able to kill a cat.