Martin Jigmar serves as the commander of the HOLY organization, the special unit responsible for policing and managing Alter users on the Lost Ground. He is a noble man driven by strong convictions regarding the protection of his kind, as he founded HOLY to provide a safe haven for Alter users who face constant discrimination from ordinary humans. His background reveals that he was an American immigrant to Japan and is recognized as the first known Alter user, though he refrains from using his power for the majority of the series.

Jigmar is a strict and prideful individual, yet he also displays kindness and a quiet, reserved nature. He believes deeply in Ryuho, regarding him almost as a son and consistently pushing him to improve. His connection to the HOLY council member Kyoji Mujo is significant, and he ultimately clashes with Ryuho in a pivotal confrontation. During this battle, he confesses to Ryuho that he was a poor father to his own son, Elian, whom he neglected and failed to spend time with. Jigmar dies following this fight, prompting Ryuho to swear vengeance against Mujo.

His Alter ability, called Alter Alias, remains hidden until his final battle. It manifests as a metal alloy covering his upper chest and arms, accompanied by a separate Alter form named Alias. This power focuses on using highly compressed air to create powerful shields and devastating shockwaves, allowing him to deflect attacks and counter with punishing blows. However, because his Alter was heavily refined through years of training and suppression, using it causes him to age rapidly, transforming him from a man in his early twenties to an elderly figure over the course of a single battle.