The Fallen & the Kiss of Dusk: The Shadowborn Duet, Book Two (The Crowns of Nyaxia #4)

"Mische made the ultimate sacrifice to save those she loves--and plunged the world into an eternal night. Now, imprisoned by the gods and obsessed with revenge, Asar is desperate to find her again. When a goddess offers them a final path to redemption--and back to each other-- Asar and Mische embark on an extraordinary mission. Together, they must seize the power of the god of death so Asar may do the impossible: ascend to true divinity"