Marcus Lithos is a character from the anime Sword Gai: The Animation. He was originally a boy who became paralyzed following a serious accident. Seeking a cure for his condition, he acquired the Azoth Sword, a legendary weapon said to house Beelzebub, and became its user. Outwardly, Marcus presents himself as a calm, affluent aristocrat, but beneath this composed surface lies an unstable and deeply traumatized individual. The deaths of his family members left him with lasting emotional scars, and he struggles with feelings of loneliness and betrayal. This deep yearning for connection leads him to simulate a family life by hiring staff to play the roles of relatives, blurring the line between reality and fantasy.

In the story, Marcus initially becomes overwhelmed by the Azoth Sword’s influence and nearly commits murder, but Naoki Miki intervenes and stops him. After this incident, Marcus manages to regain control of the weapon, and Miki subsequently invites him to join the Shoshidai, an organization dedicated to collecting and containing cursed armaments. Over the course of the series, Marcus develops from a desperate, paralyzed seeker into a capable wielder of the Azoth Sword who learns to master its power. His key relationship is with Naoki Miki, who acts as both a rescuer and a conduit into the Shoshidai. His notable ability is his command of the Azoth Sword, a cursed weapon that grants him formidable combat capabilities but also poses a constant threat to his sanity and humanity. Marcus is an anime original character with no counterpart in the manga.