Casshern was created as a synthetic being of unparalleled combat ability, originally designed to advance the creation of robotic life. However, when this purpose proved unsuccessful, he was modified into a weapon of destruction, serving Braiking Boss alongside his fellow warriors, Dio and Leda. Casshern was soon deemed the strongest of the trio, making him the ideal candidate to eliminate Luna, the mysterious figure capable of bringing balance between humans and robots.

Upon assassinating Luna, Casshern unwittingly triggered the Ruin, a catastrophic event that caused the gradual decay of all lifeforms. This act erased his memories, leaving him wandering aimlessly through a dying world, unaware of the destruction he caused. As he travels, Casshern learns the dark truth of his past, realizing that his mere presence invites fear, violence, and despair among the survivors of the Ruin. Despite this, he begins to seek redemption, hoping to find a way to atone for his sins and bring meaning to his existence.

Casshern is a sleek, humanoid machine with a strikingly human-like appearance. He has pale skin, piercing blue eyes, and long, jet-black hair, giving him an almost ethereal yet sorrowful presence. His combat suit is primarily white with black and gold accents, including a signature red emblem on his chest, symbolizing his connection to the past and his role in the world’s destruction.

Unlike most robots, Casshern does not show visible signs of mechanical wear and tear, making him appear immortal in a world where others are falling apart due to the Ruin. This makes him both feared and revered, as many believe that killing him may grant them eternal life, while others see him as a harbinger of doom.

Casshern is a deeply introspective and sorrowful figure, weighed down by his forgotten past and the destruction he unknowingly caused. He begins his journey as a blank slate, knowing nothing of who he is or why the world fears him. However, as he encounters those who seek vengeance against him, he gradually comes to understand his own guilt, leading him to question his own worth and purpose.

Unlike the remorseless killing machine he once was, Casshern develops a strong sense of compassion and remorse, choosing to help those in need rather than succumb to despair. Despite his overwhelming strength, he rarely engages in unnecessary violence, only fighting when forced to defend himself or protect others. He is gentle and soft-spoken, often reflecting on the meaning of life, death, and redemption.

However, beneath his calm and empathetic demeanor, Casshern is constantly haunted by his past sins, fearing that no matter what he does, he can never undo the destruction he caused. This internal struggle defines his journey, as he seeks to bring meaning to a world that is crumbling because of him.

• The Man Who Brought Ruin
  Casshern begins his journey with no recollection of his past, wandering a world where everything is falling apart. As he meets various survivors of the Ruin, he quickly learns that he is the cause of their suffering, making him both a target for vengeance and an object of fear. His mere presence invites hostility, desperation, and violence, forcing him to confront the consequences of his past actions.

• Discovering the Truth
  As he pieces together fragments of his past, Casshern learns that his assassination of Luna triggered the Ruin, causing all life to decay. However, when he finally finds Luna, he discovers that she has been reborn, not as a savior, but as a goddess offering false life. This revelation forces Casshern to reevaluate the meaning of existence, as he realizes that true life cannot exist without the inevitability of death.

• Confronting Dio and Leda
  Casshern eventually reunites with his former siblings, Dio and Leda, who have deep resentment toward him. Dio, who was once his equal, now seeks to surpass him in combat, fueled by jealousy and a desire to prove himself superior. Leda, on the other hand, seeks control, believing that Casshern’s power should be harnessed for her own ambitions. These confrontations serve as reflections of Casshern’s own internal struggle, forcing him to face the consequences of his past relationships and actions.

• The Journey Toward Redemption
  Through his encounters with both enemies and companions, Casshern gradually comes to accept his sins, realizing that his purpose is not to erase the past, but to guide the world toward a new future. He chooses to embrace life rather than fear death, showing others that mortality gives life meaning.