Genos, often referred to as the 'Demon Cyborg,' is a pivotal character in the anime series One Punch Man. He is a 19-year-old cyborg who becomes a disciple of Saitama, the protagonist, seeking to become stronger and avenge his family's death by a mysterious cyborg. Genos is known for his serious demeanor, unwavering determination, and strong sense of justice. Despite his immense power and advanced mechanical body, he continually strives to improve and often serves as a foil to Saitama's nonchalant attitude. His loyalty to Saitama and his quest for strength are central to his character arc.