Crimson Skies by Ava Marie Salinger

The End is Nigh…
A war to end all worlds is looming. Cassius Black and Morgan King must ready their forces for the fight against Elios, the dark God determined to raise Chaos himself from the Abyss.
With Atropos’s prophetic vision that their final battle will have Earth as its stage, Cassius embarks on a journey to New York to persuade the leaders of the human race that war is inevitable and their best chance lies with the otherworldly beings who fell to Earth five centuries ago. Meanwhile, Morgan and the rest of their team set out in search of three exceptional human mages integral to the defense of all they hold dear.
As their allies begin to assemble on Earth in preparation for the impending conflict, Elios seizes the opportunity to disrupt their preparations and sow chaos.
But the prelude to war brings an unexpected visitor to Earth, catching even the Fates off guard. And he brings with him a devastating secret.
Can Cassius and Morgan overcome this shocking new challenge? Or will the harsh reality of their destiny condemn them and their loved ones to a grim fate?