Captain Nemo, also known by his full name Eleusis La Arwall, is a central figure in the anime Nadia: The Secret of Blue Water. He serves as the captain of the advanced submarine Nautilus and leads a small crew in a clandestine war against the Neo-Atlantean forces, a militaristic organization bent on world domination. Nemo is a tall, tanned man with short purple hair, green eyes, and often wears a captain’s hat and a mustache, giving him an authoritative and enigmatic appearance.

Nemo’s background is rooted in tragedy. He is the father of the series’ protagonist, Nadia, and his past is tied to the ancient Atlantean civilization. His real identity, Eleusis La Arwall, connects him directly to the royal lineage of Atlantis, and he possesses deep knowledge of its lost technology, including the Blue Water pendant that Nadia carries. He lost his wife and his homeland to the Neo-Atlantean attack, an event that drives his mission of resistance. He commands the Nautilus, a submarine built using advanced Atlantean science, which he uses to strike against Gargoyle’s forces and protect those who oppose them.

Personality-wise, Nemo initially appears cold, distant, and stern. He speaks little and keeps his emotions tightly controlled, presenting a grim and determined front. This demeanor softens over the course of the story, especially as he interacts with Jean, Nadia, and the other allies who join him. He gradually reveals a more paternal, protective side, particularly toward Nadia, and comes to trust Jean’s ingenuity and warmth. Nemo is deeply principled, operating from a sense of duty to prevent the misuse of Atlantean power and to safeguard the future. He is not without vulnerability, however, and carries the weight of his losses and the burden of his secrets.

His motivations are twofold. On the surface, he aims to defeat Neo-Atlantis and stop Gargoyle from resurrecting the destructive might of the old Atlantean empire. On a deeper level, he seeks to protect Nadia and ensure she understands her heritage and the true nature of the Blue Water. He is willing to sacrifice himself and his submarine to achieve these goals, showing a profound commitment to his cause.

Nemo’s role in the story is pivotal. He rescues Jean and Nadia from the jewel thieves early on and offers them refuge aboard the Nautilus. From that point, he becomes a mentor figure and the military leader of the resistance. He provides the technology, strategy, and firepower needed to confront Neo-Atlantis, while also guiding Nadia toward the truth of her origins.

Key relationships include his daughter Nadia, whom he initially keeps at a distance but later protects and reveals his connection to. With Jean, Nemo develops a grudging respect, valuing the boy’s mechanical talent and courage. He also commands a loyal crew, including the stern Electra, and interacts with the former jewel thieves—Grandis, Sanson, and Hanson—who become allies. His relationship with the Neo-Atlanteans, especially Gargoyle, is one of relentless opposition.

Character development sees Nemo evolve from a mysterious, solitary commander into a more emotionally open figure. He acknowledges his paternal bond with Nadia, shows moments of warmth and humor, and eventually accepts help from others. His final actions underscore his selflessness and willingness to let go of the past.

Notable abilities include his mastery of Atlantean science, which allows him to operate and maintain the Nautilus’s advanced systems, including energy weapons, cloaking devices, and deep-sea navigation. He is a skilled tactician, capable of outmaneuvering larger Neo-Atlantean vessels. He also possesses physical resilience and combat training, often leading dangerous missions personally. His greatest asset, however, is his knowledge of the Blue Water’s true purpose and the history of Atlantis, which becomes crucial to resolving the central conflict.