Luke is a Bone Adept from Melbourne, Australia, and the son of the director of the Los Angeles Bone Research laboratory. He is one of the five Earth Bone Adepts selected to defend the planet, and he serves as the leader of the White Bone Warriors. Luke became a Bone user at a young age, almost as if guided by fate, and he has carried the weight of expectation ever since. His father’s position and his own early start have made him feel a heavy responsibility to live up to his role, and this pressure sometimes affects his judgment and composure in battle.

In terms of personality, Luke is calm, composed, and highly reliable. He takes his leadership duties seriously and is direct and clear when giving orders to his comrades. He is not one to waste words, and he expects the same level of commitment from those under his command. Despite his cool exterior, he has a strong sense of duty and is willing to make difficult decisions for the sake of the team. He is analytical and methodical, preferring to rely on practical knowledge and facts rather than emotions. This reserved nature can make him seem distant, but he cares deeply about the outcome of his missions and the safety of his allies.

Luke’s primary motivation is to protect Earth from the Dark Bone invaders. He believes in the mission handed down by the Bone Research Organization and strives to execute it perfectly. However, as the series progresses, he also learns to trust his companions more and to open up emotionally, especially after an incident in which he nearly lost control during a battle. That event forced him to confront the fear of his own power and the expectations placed on him, leading to a deeper understanding of himself and his role in the team.

As the leader of the White Bone Warriors, Luke is often the one who coordinates strategies and makes tactical calls in combat. He is a skilled and experienced Bone Fighter, wielding the Shark Bone armor. His transformation resembles a shark: the armor is slender and sharp, and the helmet is blue, shaped like the upper half of a shark with its face and fins visible. Shark Bone is a water-type Bone, which grants Luke the ability to dive beneath solid surfaces as if they were water and to swim through the ground like a shark through the ocean. In his Rare Metal state, he can perform a powerful spinning technique that engulfs his entire body in a water tornado, functioning like a drill to penetrate enemy defenses.

Luke’s relationships with the other Bone Adepts are central to his development. He starts as a commanding figure who expects obedience, but over time he learns to respect the individual strengths and wills of his teammates, particularly Shougo Ryujin, with whom he shares an important bond. He also has a complicated relationship with his father, the lab director, whose expectations weigh on him. The other White Bone Warriors—Antonio, Tyrone, and Gilbert—look to him for guidance, and he gradually becomes not just a leader but a trusted friend.

Throughout the anime, Luke undergoes significant growth. He learns to balance his sense of duty with his own emotional needs, and he becomes more willing to rely on others rather than trying to carry every burden alone. His abilities also evolve, particularly his mastery of the Shark Bone’s water-based techniques and his ability to maintain control under pressure. By the end of the series, he has matured into a leader who leads not only by authority but by mutual respect and understanding.