Hi all, I'm new to these forums and thought I'd get some suggestions from those who offer

First up, seeing as I'm still not an official owner of the Anima book (my copy is being paid off at a local store and gaming club), it has been a bit hard to find out all the details about the Anima world itself; so, instead, I decided to make my own.
Basically, I expanded on the idea of the Warriors Orochi game from the makers of Dynasty and Samurai Warriors on PS2. In this, the main villain tears holes in time and space, ripping up parts of 16th Century Japan and China during the 3 Kingdoms era, and fuses them in his own realm to test the skills of the world's 'greatest' warriors.
Instead, on my world, either a bored or otherwise motivated wizard of immense power initiated a war on their (gender still not chosen) world after strange rituals that, while they appeared to do nothing else, consumed most of the world's magical energies. The other thousands of wizards (this world has more than usual) fought each other for control of what magic and ley-lines remained, and effectively destroyed their world in the process.
It was then that the magical energies thrown around by these wizards triggered the spells set in place by the first, opening rifts across the broken world's surface. These rifts lead to other worlds, and with them brought entire countries and continents to replace the broken landscape, before sealing the newcomers from their home worlds. Somehow, the world stabilised, and the individual ecologies of those partial worlds managed not to be destroyed entirely, maintained by the strange magic that called them.
The new inhabitants hid away, hoping that they'd be returned home in time. Eventually, they realised that (in despair) they had to venture forth to make a living upon their own world. Different cultures and races encountered one another and clashed; others made peace and trade agreements.
All the while, the lands merged perfectly as though they all belonged to the same world, with only scattered remnants of the broken, blackened landscape that originally existed could be found between some borders. However, at the most northern point of the world, ranged vast Wastes of that black soil, all shrouded in a mist, and any attempt to penetrate by the suspicious newcomers have been repelled by monsters and the undead forms of the world's former inhabitants. Unknown to them, within the mists is a giant city to rival any of their own, where the wizard responsible for everything ruled over his monstrous minions; and the other survivors lived a nomadic life in the mists where their children became mutated from the concentrated magical energies flowing there.
So, here's what I wanted to ask for help for. With such a wide range of other 'worlds' brought into this one I have invented, I need to come up with at least a dozen (even basically) detailed cultures or races to add some diversity to my adventure. I'm thinking of having my future players submit some things ahead of time for my to work upon, but I'll still probably need more.
What I'm also looking for is for inspiration from existing games / movies / books / real historical events, for how to develop more societies and cultures. I'm personally thinking of throwing in a society based on the Tsuranuanni from Raymond E Feist's Magician.
I'll probably also be adding in parts of the Anima world into my own, so that all the creatures from the Core book can be included.
Any further suggestions would be greatly appreciated
