Mirror of the Sun by Victoria Sue

Together, they might stand a chance.
Divided the world might never survive.

Richard, chased by the memory of losing his entire team in Syria, agreed to help his younger brother Talon, in an attempt to forge bonds between them that had been broken when Talon had transformed.
Adam, terrified of the team that had given him a chance at life, finding out what he had done. Would it result not only in losing the family he had always wanted but never had, but the real risk of harm to those not expecting it, and knowing he was going to be forced to choose between the two?
Sawyer, torn between the real possibility that his ability was out of control, and terrified to admit it even to those who had always had his back, was secretly being drawn to both the warrior that might save the world, and the innocent that might have to sacrifice himself for it.