Age of Omicron, Season One (A Chaos Gate Series)

The Age of Omicron has begun...
Riya De Moor retired from the military to settle down and teach history. But when mythic monsters rise up to threaten the Earth, and Merlin appears in Riya's village, the veteran must fight once more to change history. Now, teacher and wizard will travel the globe, assembling a team of resurrected heroes-- relics of the ancient past, fighting to save the future.