Miras was an Atlantean guard.
He deserted the City of Atlantis when it was revealed Pasiphae would attack while the Palladium had left Atlantis' borders. He was stopped by the Colchean army outside, but was allowed safe passage out of the city in the end. (A New Dawn Part 1)
While escaping the borders of the city, he and a large force of Atlanteans came across Jason, Hercules and Pythagoras who had retrieved the Palladium from Pasiphae's grasp. He agreed to take back at Atlantis after Jason had returned it and they defeated the Colchean army, following their return. (A New Dawn Part 2)