Mardo, also referred to as Colonel Mardo, is a prominent antagonist in the second OVA episode of Crusher Joe: The OVAs, titled The Final Weapon ASH. He is a ruthless space pirate and the leader of a mercenary gang that operates outside the law. His background is that of a military officer turned renegade, and he commands a sizable force of loyal followers. Mardo is characterized by his cunning intelligence, strategic thinking, and a charismatic presence that enables him to attract and maintain a dedicated crew despite his villainous nature. He harbors a deep-seated animosity toward the Crusher organization, viewing Joe’s team as his primary rivals and obstacles to his ambitions.

In the story, Mardo serves as the main threat whom Joe and his group must confront. He becomes involved in a plot surrounding the dangerous superweapon known as Ash, a device capable of annihilating all life on a planet. His motivations are driven by a desire for power and control, and he does not hesitate to commit atrocities, including the destruction of entire worlds, to achieve his goals. He is shown to be calculating and often stays one step ahead of his opponents, making him a formidable adversary.

Mardo’s key relationships are defined by conflict. He stands in direct opposition to Crusher Joe and his team, particularly during the events of the second OVA. While he does not have personal bonds with the main cast beyond enmity, he maintains authority over his own followers through a mix of fear and loyalty. His notable abilities include exceptional leadership, tactical planning, and combat prowess, both in space warfare and personal confrontation. He is also portrayed as possessing a strong will and a willingness to take risks. Although his role in the OVA is limited to a single episode, his presence leaves a significant impact as a memorable and dangerous villain. There is little in the way of character development, as Mardo remains a consistently ruthless antagonist throughout his appearance.