Chaos Volume 1 (Books 1-3)

The first three books in the Chaos series. SoulCara Kelly's life is going nowhere when she's lured to a faery festival. There she sees darkness and magic, madness and lust, and she comes out the other side with new eyes and an addiction to the fae. When the faery who saved her life returns to her, Cara knows there's something wrong. Two souls exist in one body, and both need her, but to help one, she'll end the life of the other.
At first, her mind is made up, but both souls know how to charm her. As the days pass, it becomes clear that the faeries need a leader, and Cara finds herself sucked into a world where morals don't exist. The truth of her past is hidden in the magic, but all Cara needs to do is survive the king's coronation, then the fae will let her go forever. But that's not what she wants anymore, and it's getting harder and harder to tell the difference between a king and a half-blooded solitary fae.
Cara's losing her way, and her heart, to the fae, but there's still her life, and her humanity, left to lose. FadeCara Kelly should have left the faery realm now that it has a king to rule all, but nothing is that simple. The real king is trapped in the Fade, and Cara's journey is just beginning. Guilt-ridden by the fact Brendan's soul was sacrificed for hers, she's determined not to desert him after his one pure act of goodness.
Time is running out; even if she makes it past all of the dangers of the Darkside, a shade might await her in the Fade. Running from enemy and friends alike, she sets out on a path that will lead headfirst into danger. Even if Cara makes it to the Fade, even if a goddess watches over her, she doesn't trust all of her companions, she still has to find a way home, and freeing Brendan could cause a war between the faeries she cares about.
And all the while, Chaos grows unchecked. QueenThree kings. Two queens. One heir. Chaos will rule...