Half Bad is obsessed with the question of identity. Because Nathan is half Fairborn and half Blood Witch, he doesn’t know who he is. Worse still, neither of his parents is present during his formative years to help him decide. His mother’s suicide and his father’s absence force Nathan to rely on his stepfamily for definition. What complicates his struggle is the loaded moral judgments attached to being Fairborn or Blood. When he is only four, Nathan’s sadistic sibling Jessica happily points out his failings and labels him evil because his father is perceived that way by Fairborns.

For his part, Nathan functions much like a blank slate. He has no innate sense of who he is to counter the judgments being forced on him by others. Because Fairborns raised him, he initially thinks this group is better than Blood Witches. He radically changes that opinion after repeated abuse by Fairborns and their Council. Just as the Fairborns maintain a singular focus on eliminating all the Blood Witches in the British Isles, the Bloods adapt by submerging their own identities so they can move among the Fairborns. While Nathan struggles to find his true identity, he must also work to determine the real identities of potential friends among the Blood faction.