He Who Breaks The Earth by Caitlin Sangster

Mateo spent years believing he suffered from a strange wasting sickness, but he’s finally learned the much darker truth. Now he will do whatever it takes to save himself, even if it means betraying Lia, the one girl who’s ever made him care about something besides his research. It doesn’t help that his father kidnapped the last living member of Lia’s family, and Lia is only coming back into Mateo’s life to hunt him and his father down for revenge.

Anwei’s rage can’t be contained after the disaster at the tomb that ended with Knox almost dying. Worse, she learned that the brother she’d been desperate to avenge has been living a life of luxury, raised by the monster of her nightmares. With the power of an ancient, nameless god running in her veins, Anwei vows to end the shapeshifter once and for all.

But the members of her crew each have their own motivations—and their own gods whispering in their ears. As Anwei gets closer to the shapeshifter she’s chased for so long, she realizes the gods’ plans and her own might diverge. But she will destroy anyone standing in the way of her revenge.