Ok, first, I want to get a few notes out of the way before I turn you all loose to create your characters when I get a character sheet together.
http://lostgirl.wikia.com/wiki/Category:Species Known Fae Species list.
http://lostgirl.wikia.com/wiki/Light_Fae Lost Girl wiki page. (Source reference material.)
PoliticsThe leaders of the Light Fae are named after sacred trees.
There is a local leader, The Ash and the High Council of High Elders, which conducts meetings with The Ash as a chairman.
There is also an overall governing body, a Council with The Blackthorn as a representative.
The relationships between the various Noble families that lead the Light Fae are volatile at best. None trusts the others and all think the others capable of assassination and manipulation for their own family's benefit. Despite the impending threat of the Garuda, they seem unwilling to cooperate.
CharacteristicsMembers of the Light Fae may eat humans but according to The Blackthorn they do so only for food, not sport. Otherwise they seek to protect the humans if they can.
The difference between Light Fae and Dark Fae is not the same as the difference between Good and Evil.
(Basically, there's a lot of shades of gray between the two to sum it up.)
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http://lostgirl.wikia.com/wiki/Dark_Fae (Source reference material, same as before.)
PoliticsLike the Light Fae, the Dark Fae have their own group of leaders and elders. While the Light name their leaders after sacred trees, the Dark title their leaders with the names of fallen warriors.
The Dark seem to hold the monopoly on the industrial and criminal elements of the city. Everyone is expected to pay a quota to The Morrigan from their businesses, and punishments are considered "unpleasant" if the quotas are not met.
Unlike the Light, who follow a strict set of rules, the Dark appear to follow no rules but their own. They are, however, respectful of the Old Laws like Blood Oaths and those governing territory. Despite animosity with the Light, it is made clear several times that the Dark have no interest in another Great War.
CharacteristicsMany of the Dark Fae are portrayed as amoral and corrupt operating in activities that others would consider criminal and cruel. While many members of the Light practice restraint and control, many Dark revel in their abilities; embracing what their power for whatever means they so choose. While they do dispose of their human kills they are known for leaving a higher body count than the Light and according to a Light Elder have no qualms with murdering for pleasure as well. Essentially what sets the Dark Fae apart from the Light is their willingness to use their unique gifts purely for personal gain regardless of the consequences to those around them, especially humans.
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To put it simply, the Light and Dark aren't as clearly defined as they might seem at first glance. There have been evil Light Fae before, just as there has been good Dark Fae, but the general idea would remain the same though. Dark Fae see humans as mere sport more times than not, while the Light see us as food but they try to protect their food source as best as they can. Both sides do not want another Great War so let's try to avoid that shall we?

Ok, setting wise I think someone said Boston so if everyone's cool with that we'll set this up there given its rich culture and history. And before I forget, as I said once before, I do not want anyone trying to play an Under Fae, which are Fae that are either A, more animal like in their appetites and personalities, if they even have sentience beyond the animal level, or B, they cannot pass for human because of their outer appearance or because of how they act in general. For example, in one episode a man like Fae in appearance, dressed as a human and everything, was locked up in the Light Fae's dungeon due to how dangerous he was since he used his telepathic abilities to use the Fae that happened to be closest to him at the time to commit suicide. They classify him as an Under Fae though since he was more interested in harming others than trying to blend in. Hence why I don't think any Under Fae would work in this. One last thing, there can not be another Ash, Morrigan, or Blood King given how powerful they are in the Fae world and also because they are located elsewhere in the world anyway, beyond that anything else is up for grabs pretty much unless I say otherwise.