Dean Hanos is a central character and a member of the Geisters, an elite anti-creature special unit operating directly under the Yuno family. He holds the rank of Lieutenant. Following the death of the previous commander, Leon Wilters, Dean succeeds him as the leader of the Geisters.

Dean is characterized as an introverted individual with a somewhat indecisive nature. His leadership qualities are noted to be less developed compared to his predecessor Leon. Despite these personal tendencies, as a member of the Geisters, which consists only of the Yuno family's most elite soldiers, Dean consistently demonstrates outstanding skill in combat.

His background is rooted in a family history of service. Dean was born to Odion Honus, a fellow member of the Geisters, and Nona Honus, a scientist in the employ of the Yuno family. Both of his parents died when he was very young, leaving him with few memories of them. As a result, Colonel Lambert, who had a close relationship with Odion, acted as a father figure to Dean.

Throughout the story, Dean is haunted by nightmares and experiences strange phenomena, such as hearing the auditory hallucinations of a girl. His motivations are deeply personal, driving him to uncover the mysteries surrounding these visions and the truth of his past.

Dean shares several key relationships that define his role in the narrative. He has been a close friend of both Alkyon and Captain Leon since childhood, though in his professional life he does not get along well with Alkyon. When a new member named Shai Tanna joins the Geisters, Dean shows her a great deal of care and concern. This concern is demonstrated when he goes alone to the Sarakia Tower to retrieve Shai after she is framed for assassination and imprisoned, an act that leads to his own capture and torture. He later goes into exile with Shai and another ally, Siol, and eventually starts a family with Shai after the resolution of the main conflict.

Dean's character undergoes significant development as he learns the truth about his parents. He is shocked to discover from Leon, who he thought was dead, that his parents died because of actions related to a being named Inanna. From Inanna and a girl named Pira, he learns the full truth and discovers that Pira is actually his half-brother. This revelation causes him to mentally wander, grappling with feelings of betrayal and skepticism towards the Yuno family he has served. He eventually leaves to meet his own father, Odion, who has been transformed into a creature. After hearing his father state that he does not resent Inanna, Dean calms his internal conflict and returns to the battlefield to defend his home. At one point, Dean is believed to have died from injuries sustained when the De Beers cannon destroys a location called Atlantis Island. However, his father Odion gives up his own life to revive him. As a result, Dean's Mega Suit is upgraded to a Giga Suit for the final battle.

In terms of notable abilities, Dean is a highly proficient fighter, which is standard for a Geister. He pilots a Mega Suit, which later receives an upgrade to a more powerful Giga Suit. These suits enhance his combat capabilities, allowing him to face the dangerous creatures that threaten humanity. He ultimately survives the final battle and the collapse of the main antagonist.