As Nemo is in charge of the ship, he is tough on both himself and those around him, and he has little patience for indulgent behaviors, idleness, or selfishness. He is the consummate captain—tough as nails and possessed of a militaristic bearing. At the same time, as he is also Triton, he gives his blessing to all manner of adventurous journeys. Upon his summoning as a Servant in Chaldea, he deems Protagonist a travelling adventurer, and so offers his blessings and guidance.

At first, he adheres rigidly to his given role, hiding his true self and insisting that he is "just a submarine" even in his interactions with Master. Gradually, as he lets down his guard on recognizing his Master is trustworthy, he becomes much more companionable, even friendly. Naturally straightforward and goodhearted, he will never betray those to whom he's taken a liking.

Even if he cannot see the end of his friend's travels, he numbers among the Heroic Spirits who truly loves mankind, and so will always offer his blessings to humanity.

Operating a submarine, much less a warship, would be impossible for even Nemo to do alone. Knowing Nemo’s hands would be tied, Sion applied one of the Atlas Intuition’s secret techniques known as “memory partition” at the time of Nemo’s summoning. As a result, by dispersing his own magical energy, Nemo is able to create clones that are essentially the same as him but specialized for the various roles needed for the operation of a submarine. The following are the Nemo Series that work in the docks.

Nemo Marine
The most nimble of the series, there are always twelve of these (twelve active on duty, maximum twenty-four). They all have the same personality and appearance. Nemo Marines represent the labor force that cleans, operates, maintains, and performs other miscellaneous tasks around the ship. They are always cheerful and never hate anyone (though they may not like everyone). While they may scream and shout a bit in emergencies, they will always do their very best to resolve the problem. The Marines are also the members of the Nemo Series in whom Triton's aspects are most clearly expressed.

Nemo Professor
Professor addresses everyone respectfully, which won Blackbeard’s friendship. As the name suggests, Professor works as the ship's resident intellectual and strategist, and is in charge of analysis, calculation, and devising strategies.

Nemo Engineer
The stubborn chief engineer who runs the ship's engine room with a fierce workman's spirit. Hers is one of the most dangerous and demanding jobs on the ship and she is driven by her motherly love and belief that protecting humans is her duty. She also sees herself and Captain as equally ranked, and so thinks she can take his place if he ever screws up. She loves humanity a great deal, but loves the Nautilus just as much.

Nemo Nurse
She is in charge of the infirmary and is the most mature, as well as tolerant and rational, of all the Nemo Series. Nurse always performs her duties with a cool head in an emergency.

Nemo Baker
Baker is the member of the Nemo Series in charge of the most important part of the ship: the galley (bakery). Meals boost a soldier’s morale, so ultimately this is the most powerful Nemo.

When Sion summoned him at the start of Part 2, he was still both a mermaid and a prince. But after joining Chaldea and deciding to help them out, he sealed up his mermaid self and fully embraced his Captain Nemo side in the name of conquering Atlantis. He later became the captain of the dimension-piercing battleship Storm Border and assisted in the battle for Novum Chaldea.












He LOVES parfaits.
(He treats this fact as top secret information of the highest clearance level.)