Rurou Arthur serves as a main character in the anime series *Million Arthur*. He is an adult male with gray hair reaching chest length and eyes described as blue or petrol-colored. As one of the Arthurian Knights, his duty is to protect the kingdom of Britain from threats arising across various time periods. He wields the sacred sword Excalibur with skill in combat.

Rurou demonstrates proficiency in dual-wielding weapons and is characterized as a gunslinger, indicating versatility in both ranged and close-quarters engagements. He is recognized as a capable strategist, frequently formulating plans to counter opponents during missions. His personality blends a strong sense of justice with humility; he prioritizes protecting others and opposes oppression or tyranny, consistently aligning his actions with ethical principles. Despite his combat prowess, he places the needs of allies above his own.

Analyses identify his personality as ENFJ (Extraverted, Intuitive, Feeling, Judging), reflecting traits including empathy, intuitive problem-solving, and values-driven leadership. He is also categorized as an Enneagram Type 8w9 ("The Challenger"), highlighting assertiveness, independence, a desire for justice, and occasional defensive reactions when challenged. These frameworks contextualize his leadership style and motivation to safeguard others.

Within the narrative, his role involves collaborating with other Arthur avatars to preserve historical integrity.