Nightcrawlers. The Daywalkers Duology

"Make them listen and make them see, even if you have to scream until your lungs give out, even if you have to fight until your hands are bloody."Eric and James MacNamara were adopted into The Colectiv, a vampire-hunting organization of heartless violence. They were driven by a blind need to make the world a better place, but when they found their lives were a lie, everything came crashing down. In response, Eric forsook The Colectiv, and now the inseparable twins are wrenched apart, one in a cell and one on the run with Emilia-a wanted vampire he sacrificed everything for.
Commander Michael Iovaneau has sent a pack of hunters after Eric in retaliation, while he stays in Romania to siphon valuable information from James. Through rigorous interrogations, James puzzles out a means of escape, mulls over his identity, and forms an unlikely friendship with a fellow cellmate. All must face the consequences of their actions and make decisions for the sake of love and survival.
But Michael's not the only one searching for Eric. Wade MacNamara, his biological father, is also hoping to reunite after a 20-year underwater imprisonment. Eric's vengeful mission to kill Dante is no more, yet that wrath finds itself locked on an entirely new target: Michael himself. Will Eric's fury consume him, or will love be enough to save him from the edge again?