Okay, so I just woke up from having a pretty strange but awesome dream, so I'm gonna use that as inspiration for my first character. I did read your plot overview, however there are so many details and organizations, so you'll have to help me decide my character's placement in this realm. :)
This first character will be female, and she has a great amount of power. I imagine she will be apart of one of the armies, and be a great threat to the others. Killing her would be a huge mistake, rather I believe the goal should be to capture and subdue her for future uses, such as ransome, etc. Her power comes from her use of fire (I think. The dream was vague on this part).
I think I want her name to be Efkina, and she'll have wavy dark brown hair and brown eyes, olive skin, and a cultured nose(based off of traditional Greek attributes). Since I speak broken Greek, I will have her also speak rough Greek from time to time.
Efkina is not very educated, however she is "streetsmart" and is a dependable person to lean on. She is often distant and doesn't enjoy simple and silly fun, and despite that, she does enjoy having friends around who accept that quietness about her. She would much rather choose to be good and right in her ways than be authentic, which will be a massive downfall in her social life.
In battle, she is fearsome and well guarded. She does not fight out of anger, rather she fights with justice and divinity in mind. This is where she finds everything to make sense. When she is fighting for her people, she finds clarity and peace amongst the chaos and tragedy of battle.