Xaden is an exceptionally handsome former aristocrat turned rebellious dragon rider. His family were slaughtered by Violet’s mother, Lilith Sorrengail, in the seditionist uprising. Avenging the death of his father, the rebel leader Fen Riorson, is never far from the top of his mind. Xaden, especially at the beginning of the novel, is defined by his identity as a “marked” person, a child of the Rebellion condemned and distrusted by society due to their parents' traitorous acts. This label defines his social status within the War College, where cadets like him face prejudice, suspicion, and heightened expectations of failure because of their background. In addition to his dragon relic, a huge tattoo that dragons confer on all riders when they make their lifelong bonds, Xaden is also covered with scars from punishments meted out to deter other rebel children from misbehaving or further sedition. On top of this, he and all of the other marked children have large, disfiguring marks in visible places on their bodies, a magical punishment meant to visibly distinguish them from the children of people loyal to Navarre. Xaden chose to guarantee that some of the children of rebels could attempt to redeem themselves by becoming riders; some of his scars are a record of this agreement. If any of them step out of line, he dies.
Unsurprisingly, given all this, Xaden begins the novel full of hatred and resentment. He’s a talented warrior and magic-user bonded to one of the most famously vicious and powerful dragons in Navarre, the navy-blue Sgaeyl, but he still has to fight for his position every day. He’s the Wingleader of the Fourth Wing, one of the subdivisions of the cadets at Basgiath. Because he has experienced so much loss and has been raised to distrust anyone without a rebel relic, Xaden is emotionally withdrawn almost to the point of stuntedness. He’s a kind person at heart, but he has been forced to become a grim, success-oriented killer in a world that views him as a threat. All of his experiences have forced him to hide vulnerabilities and suppress emotions wherever he can. He keeps intense control over his feelings, rarely allowing others to see any sign of weakness or uncertainty. He approaches every interaction defensively, especially when he’s speaking with those in power or un-marked cadets. This emotional barrier initially makes Xaden appear detached and unapproachable, and Violet begins the novel terrified of him. As he’s publicly promised to murder her, this fear takes a while to wear off.
Xaden’s relationship with Violet begins with distrust and tension. As an un-marked cadet and daughter of a high-ranking officer, Violet represents the worst parts of the establishment that destroyed Xaden’s life and his family. However, Xaden also can’t deny his quickly growing feelings for Violet, as much as he tries to resist them. He quickly realizes they will have to cooperate when Violet bonds with his dragon’s mate and the two humans can suddenly sense each other’s thoughts and emotions. Slowly but inexorably, he begins to recognize her as an ally, and then as something more. Throughout the novel, Xaden struggles to balance his growing infatuation with Violet against his ingrained distrust of any Sorrengail. Their relationship brings out his more compassionate side, a part of him that he usually keeps buried. Violet’s empathy and openness encourage him to lower his defenses, although they often snap back up quickly when he feels she’s gone too far or he’s too vulnerable. Xaden’s evolution in Fourth Wing is all about relinquishing his iron grip on hatred and resentment. His journey with Violet forces him to confront the emotional stuntedness that years of hardship and distrust have created. By the end of the novel, Xaden has begun to realize that people don’t have to be defined by their background. So much so, in fact, that he invites the very Sorrengail girl he once swore to kill to be his right hand in a Rebellion of his own devising.