Aston is the former leader of the adventurer party known as the Golden Phoenix, which was famous for defeating A-rank magical beasts without sustaining injuries. He is depicted as a tall, imposing man with short red hair and a stern expression, typically wearing silver armor accented with gold trims and a flowing red cape.

Aston's personality is defined by arrogance, entitlement, and a manipulative nature. He perceives himself as a superior adventurer and exploits those he considers beneath him. His character is driven by a deep-seated obsession with social climbing and gaining favor with the nobility. This motivation stems from a tragic past: his younger sister died because he could not afford treatment for her illness, which instilled in him a desperate need for status and security to prevent such powerlessness from affecting him again.

In the story, Aston serves as the initial antagonist who sets the plot in motion. He recruits Zenos, a self-taught healer from the slums, into the Golden Phoenix. Despite Zenos's exceptional healing abilities and mastery of reinforcement magic, which made the party famous for its flawless victories, Aston and his team fail to recognize his value. Instead, they treat Zenos as a servant or slave rather than a companion, ultimately deeming him useless and banishing him from the group with a single gold coin as severance. This decision proves disastrous for Aston. On their first mission without Zenos, his party struggles and suffers severe injuries, causing them to lose the favor of a powerful noble. Frustrated and desperate, Aston goes to the slums to persuade Zenos to rejoin, but Zenos rebuffs him by demanding an exorbitant fee.

Key relationships define Aston's arc. His relationship with Zenos is central, moving from exploitative employer to a man who is bested by and ultimately dependent on the healer he discarded. He also has relationships with his party members, including Yuma and Andres, whose near-death experience without Zenos's healing highlights Aston's over-reliance on the former member. Aston briefly attempts to hire a healer named Umin, but she quickly leaves his group due to his arrogant demeanor.

Aston undergoes a significant development. After failing to rehire Zenos, he is tricked by an evil sorcerer known as The Guide into becoming a giant golem to wreak havoc on the slums. During the rampage, Zenos manages to stop him by taking the difficult and risky route of slicing Aston out of the golem piece by piece, healing his flesh before the stone could fuse to him permanently. As a result of this near-death experience and being saved by the very person he wronged, Aston has a change of heart and apologizes to Zenos for his treatment of him. While not fully forgiven, this event forces a complete reevaluation of his life. In a final act of symbolic retribution, Zenos knocks Aston unconscious, takes his legendary sword to pay for rebuilding the slums, and leaves him with only a single gold coin to start a new life.

Regarding his abilities, Aston holds the title of a certified adventurer, but his actual skills are considered average at best. His success as a leader was built entirely on an overreliance on Zenos's healing, which masked his own inadequacies. Without Zenos, his limitations become immediately and painfully evident.