The Unvanquished is a bildungsroman, or novel of self-development. In such a novel, the main character grows from a child to an adult. The central preoccupation of such works is usually with what that character learns and how he or she changes over the course of time. This is certainly true for Faulkner's novel, especially since Bayard controls our perception of the world around him: we can see nothing he does not see. Thus, his personal and moral development is of profound importance.
At the beginning of the novel, Bayard enjoys an idyllic childhood despite the war, as depicted most clearly in "Ambuscade" and "Retreat." Bayard seems happy and relatively carefree—the first image in the novel is of him contentedly playing with his friend Ringo. There is no mention of his mother—an unusual omission—but Bayard nonetheless enjoys a warm and protective family, including his grandmother and Louvinia. (As a child, Faulkner was closest to his own mother, Caroline Barr, who was like a second mother to him; he dedicated Go Down, Moses to her.) We can clearly see his character traits, especially his courage, in his early exploits, but there are no harmful consequences to his actions: his gunshot only kills a horse, and Colonel Dick takes pity on Granny; he is rescued from his wild pursuit of the mule thieves by Colonel Sartoris, and Granny finds her way home unharmed.
The critical event in Bayard's life is, of course, Granny's death and his successful pursuit and capture of Grumby. Granny's murder matters not just because of her central role in his life but because he can plausibly be held responsible—knowing in his heart what would happen, he could have held her in place but did not. In this passage Bayard twice mentions his age, as if to emphasize the huge gulf between his life before the murder and after. In the next chapter, when Uncle Buck tells Grumby he is dealing with "children," the irony is palpable, for Bayard has obviously become a grown man.
As a grown man in "An Odor of Verbena," Bayard represents the possibility of a new moral order for the South. The traditional South, as represented by the Sartoris family, is caught up in a destructive cycle of violence and retribution, one that claims Granny's life and, in a separate cycle, Colonel Sartoris's. By confronting Redmond unarmed, Bayard retains the best part of that tradition—the concept of honor—while dispensing with the need to shed blood. It is a hopeful end to the novel for Bayard and his countrymen alike.