Babylon is a recurring character known for his distinctive abilities and composed demeanor. He is a male character with green hair and a tall, lean, athletic build. His most defining physical trait is his supernatural flexibility, which allows him to contort his body in almost any way imaginable. This ability has earned him the nickname the Giant Rat of Babylon, as he can move through spaces as small as a mouse's passage.

Babylon possesses a calm, polite, and highly sociable personality. He is often seen with a mysterious, narrow-eyed smile and has a characteristic laugh, sometimes described as a quiet kuku. Despite his friendly and gentlemanly demeanor, he is a skilled and pragmatic fighter who does not hesitate to use lethal force when the situation demands it. While he appears cool and somewhat inscrutable, he is deeply caring and loyal towards his comrades, treating them as a surrogate family.

His background is rooted in a dark past before he was saved by a man named Jade, who gave him a new purpose and a place to belong as part of a guild of assassins. This guild is composed of individuals who, like Babylon, possess unique physical traits. Babylon's motivations are largely driven by a profound sense of loyalty and gratitude. He holds a deep admiration for Jade, the former guild leader, whom he considers his benefactor. After Jade's death, Babylon transfers this unwavering loyalty to Lloyd, the seventh prince, whom he serves as a faithful retainer and addresses as Master Lloyd. He is willing to risk his life for Lloyd, not only out of duty but also in gratitude for the positive changes Lloyd has brought to their lives and for avenging Jade.

In the story, Babylon serves as one of Lloyd's primary retainers and a key member of his inner circle. His role often involves accompanying Lloyd on his various endeavors, such as joining the church to help the prince learn divine sorcery. He also takes on solo missions, utilizing his keen instincts and flexible thinking to handle delicate situations. Babylon's relationships are central to his character. Beyond his devotion to Lloyd and his late master Jade, he is very close to his other guildmates, including Ren, Galilea, Talia, and Crow. He also shares a notable bond with the nun Escher; he is known to secretly cook for her when she is hungry at night, and the two are often romantically linked by others in the story.

Babylon's development is tied to mastering his unique body. Initially unable to control his extraordinary flexibility, he was once called the Cursed One of Suppleness. Through Lloyd's guidance, he learns to channel and fully exploit his power, turning what was once a curse into a formidable combat asset. His notable abilities center entirely on his super-flexible body, a power sometimes referred to as Soft Body of Noroware. He can twist his muscles and bones to their limit and release them for explosive strikes capable of breaking rock, relax his body to absorb almost any impact, or even shift his internal organs to avoid fatal injuries. Under Lloyd's tutelage, he also begins to learn how to use ki by adapting his breathing, utilizing his flexible lungs to overcome his natural shortcomings in this area. Outside of combat, Babylon is celebrated for his exceptional cooking skills, which have made him very popular among the nuns and clergy.