The Twilight Kindred are the Dark Elves of Kings of War. They had a full army in first edition, but have been reduced to a .pdf file in second edition. This is because the faction is undergoing a full fluff and tabletop redux, set for an official release in the fourth quarter of 2016 alongside Ophidia and the Northern Alliance in a campaign supplement.
Dwelling in the Twilight Glades, located east of Northern Kindred lands, north of the Empire of Dust, and west of Ophidia, the Twilight Kindred are the dark hearted cousins of the other kindred. Ostensibly aligned with the Abyss, these elves have been seen fighting alongside various shades of demons on many occasions. Likewise Twilight Kindred assassins have been seen operating in Ophidia, so at a minimum their allegiances are to the darker nations.
The Twilight Glades were at the heart of the corruption that followed the shattering of the Fenulian Mirror, for it was here that that event took place. A vast, shadowy forest covers this land, but somewhere in it's maze lies the city of Ileuther. The ambassadors of other elvish kindred are welcome here, perhaps being the only foreign presence that is safe in the Twilight Glades. The city is ruled by the Mage-Queen Laraentha Silverbranch.
Here all elves are equal, and in fact many merchants of the other kindred operate within the confines of the city. Members of the Sylvan Kindred in particular are known to visit Ileuthar often and it is a beloved city among their number; it is even said that the hand maidens of the Mage-Queen all hail from their kindred and not from her own. The city is likewise coveted by many non-elves, perhaps most prominently Mhorgoth the Faceless and his undead horde.
The city is also home to the Glade of Ways. This magical portal is protected by the eldest trees of the Twilight Glades and leads to a realm called the Shadow Paths. This realm exists on another plane of existence and is said to be able to reach other dimensions and planets. The Twilight Kindred protect this realm and usually refuse to even use it themselves for they can foresee how dangerous such a tool can be.