Otto is a serious, gentle boy who grows up entirely isolated from the violent world of 13th-century Germany. Raised by monks after the death of his mother, he learns Latin and embraces a philosophy of absolute peace and compassion. When his father reclaims him at age twelve to learn the ways of a robber baron, Otto is horrified by the brutal reality of his family's legacy. He simply does not comprehend the logic behind warfare and refuses to participate in it.

Baron Conrad is the fearsome ruler of Castle Drachenhausen. He sustains his household by acting as a robber baron who pillages nearby towns and merchant caravans. Despite his brutal nature and willingness to kill his enemies, he holds a fierce, unyielding loyalty to his family. He attempts to honor his late wife's wishes by placing their son in a monastery, but his firm belief that a man must fight to survive ultimately drives his decisions regarding Otto's future.

One-Eyed Hans is a fiercely loyal servant to Baron Conrad. Despite his short stature, he possesses immense physical strength and a clever, observant mind. Though he is blind in one eye, he misses very little and commands both fear and respect among the inhabitants of Castle Drachenhausen. He is willing to execute his master's commands without question.

Brother John is a gentle monk who helps raise Otto from infancy. Having sustained a childhood injury that left him with an intellectual disability, he cannot read or write, but he possesses a pure, simple religious devotion. He spends his days sharing stories and spiritual visions with Otto, deeply influencing the boy's moral framework.

Abbot Otto is the patient head of the St. Michaelsburg monastery and the great-uncle of young Otto. Though he currently lives a life of quiet sanctitude and study, his soft demeanor hides a past familiarity with war and conflict. He provides a safe haven for his grand-nephew, hoping to shield the boy from the violence of the outside world.

Pauline is the young daughter of Baron Henry, growing up in the rival fortress of Trutz-Drachen. In stark contrast to her father's aggressive nature, she is deeply empathetic. She rebels quietly against the cruelty of her household by seeking out gentler perspectives and offering comfort to those suffering under her family's rule.

Baroness Matilda is the wife of Baron Conrad and the mother of Otto. She is a kind woman who wishes for a life free of violence and theft. Her fragile constitution and deep distress over her husband's dangerous raids leave a lasting impact on how her son is raised following her untimely passing.

Baron Frederick is the lord of Castle Trutz-Drachen, known as the "Dragon Scorner." He stands as the primary rival to Baron Conrad. Their fierce territorial disputes over the surrounding lands and merchants fuel a bitter, generation-spanning feud between the two households.

Baron Henry is the nephew of Baron Frederick and inherits the leadership of Castle Trutz-Drachen. He is an unforgiving lord who perpetuates the brutal cycle of violence in 13th-century Germany. Driven by vengeance, he actively plots the downfall of Castle Drachenhausen and anyone connected to it.

Ursela is a nurse at Castle Drachenhausen who takes on the immediate care of infant Otto. She remains a fixture in the castle when Otto returns as a young boy, sharing stories of the family's violent history. She is fiercely protective of Otto but physically helpless against the violent forces of the era.

Schwartz Carl is the watchman at Castle Drachenhausen. He lives in a small house atop the tower with his family, tasked with ringing the warning bell whenever wealthy merchants pass through the valley. His signals trigger the Baron's raiding parties to deploy.

Emperor Rudolph is the newly established ruler of the Holy Roman Empire. Attempting to bring order to a land long plagued by lawless robber barons, he requires the local lords to answer for their violent acts and submit to imperial justice. He provides a stabilizing political force in a chaotic time.