Arthur

Arthur is intensely devoted to Shalott and addresses him as his master. He displays pronounced masochistic tendencies, taking pleasure in punishment and pain, particularly when it comes from the person to whom he has pledged himself.

That behavior masks a deeply self-sacrificing attachment. Arthur's loyalty is not based simply on Genesis's hierarchy; his bond with Shalott predates their role as defenders of the aircraft carrier and was formed under the brutal conditions experienced by the second-generation Gravity Children.

His apparent submissiveness therefore coexists with considerable resolve. When Shalott is threatened, Arthur can push his own abilities far beyond what his initial presentation suggests.

Arthur follows the Over Road and serves as Genesis's Rumble King. The Road absorbs, compresses and redirects incoming airflow, turning an opponent's force into material for defensive or retaliatory techniques.

His Rumble Subregalia is implanted within his body. When activated, four turbine structures manifest where his lungs would normally be, allowing his body itself to perform the compression functions associated with the Rumble Regalia.

Mirror Country is a coordinated technique with Shalott. Arthur draws the enemy's attention and attacks while Shalott uses mirror-like optical effects to strike from hidden positions, creating the impression that damage inflicted on Arthur is being reflected onto the attacker.

Arthur's unusual anatomy is the result of a desperate operation: his original organs were transplanted into Shalott, while the Rumble Subregalia was placed inside Arthur. Despite this, he can later fight Lind at an exceptionally high level after Shalott is incapacitated.

Arthur appears aboard Genesis's aircraft carrier as one of the six Kings assigned to defend the base. His battle alongside Shalott demonstrates that the second-generation Gravity Children include riders specifically developed around Regalia-class combat.

The pair confront Agito Wanijima and Kaito Wanijima, initially confusing them with Mirror Country and the apparent reflection of attacks.

Arthur and Shalott's history reveals that Arthur was once considered one of the weaker children in the brutal selection process overseen by Nike. Shalott deliberately provoked him in an attempt to force him to survive, only to be severely injured himself. Arthur then volunteered his organs for the operation that saved Shalott, receiving the Rumble Subregalia in exchange.

After Shalott is lost during the battle, Arthur continues fighting Lind alone, revealing a level of power far beyond what his earlier dependence on their combined tricks suggested.

Shalott is Arthur's master, closest companion and combat partner. When Shalott is critically injured during their childhood, Arthur volunteers his organs to save him, while the Rumble Subregalia is implanted into Arthur's body. Their survival becomes physically intertwined as well as emotional.

Nike Takeuchi oversees the violent selection process endured by Arthur and Shalott as second-generation Gravity Children. His treatment of them is central to the trauma shaping their relationship.

Agito Wanijima is one of Arthur's principal opponents aboard the aircraft carrier.

Lind takes control during the confrontation and forces Arthur to reveal the true extent of his ability after Shalott is incapacitated.

Kaito Wanijima fights alongside Agito Wanijima against Arthur and Shalott.

Minami Rinta performs the operation that transfers Arthur's organs to Shalott and places the Rumble Subregalia within Arthur.