To Shatter the Night By Katherine Quinn

After escaping the mist, Kiara and Jude are pursued by a vengeful god hell-bent on stopping them from breaking the curse that torments the realm, in this sequel to the highly anticipated debut YA fantasy, To Kill a Shadow…

The Mistlands Duology is best enjoyed in order.
Reading
Book #1 To Kill a Shadow
Book #2 To Shatter the Night