James MoriartyWP (ジェームズ・モリアーティWP, Jēmuzu Moriāti?), Class Name Ruler (ルーラー, Rūrā?), is a Ruler-class Servant summoned by the Alien God but contracted with the "Alien World" in the Grand Orders of Fate/Grand Order. He is later summoned by Ritsuka Fujimaru in the Grand Orders of Fate/Grand Order.
James Moriarty has been summoned in his youth, from an age before he met Sherlock Holmes. He is a conglomerate Servant, combined with the NornsWP from Norse mythology. He is an Apostle of the Alien World as he is not contracted to the Alien God itself, but with the system they use to summon Apostles. Despite using the same system, he is not loyal to the Alien God and seeks to oppose their plans, thus needs to ally with Chaldea. However, due to his dislike for the Protagonist for their role in allowing the Alien God's advent, he seeks to contract with Kadoc Zemlupus, take over Chaldea, and replace the Protagonist with Kadoc as the Master against the Alien God.
He was summoned due to his compatibility against Sherlock Holmes, who is an unknowing rogue Apostle of the Alien God who sealed his own memories in order to ally with Chaldea. Moriarty's mission was to restore Sherlock's memories and expose him as an Apostle, then defeat him when he became compelled to follow the Alien God's role for him, ridding Chaldea of their secret traitor for when he takes control.
A slightly better person than the older Moriarty, with something of a fragile self-esteem. He has a promising future filled with hope, but he has already made the most important choice of his life: to relentlessly brave the path of evil.
He faces others as a cheerful and likeable young man who loves mathematics and is always making calculations. He is the sort of person you'd be friends with in college who would insult you while lending you his notebook. But because he knows he will become a famous criminal mastermind in the future, he is trying to be evil in order to emulate his future self.
His memories of Sherlock Holmes are not very clear since he was summoned in a body from before Moriarty and Holmes met. Though he says Holmes is just an obstacle to him, he can't get Holmes out of his head.
Traum: Death and Revelation World
The NornsWP that are fused into his Spirit Origin give him the ability to manipulate fate. He can neutralize attacks by establishing that he isn't fated to be hit by them, and remove obstacles by establishing that he is fated to overcome them. However he cannot stop his own ultimate destiny. Because in Arthur Conan Doyle's books Moriarty died in a duel with Holmes at Reichenbach Falls, when Holmes dies at that waterfall in the Traum Singularity Moriarty reaches the end of his fate and also begins to disappear.
- Independent Action (A Rank):
- Conspiracy Creation (EX Rank): A Skill similar to Territory Creation. It allows him to stretch out a spider web of schemes. Its rank was supposed to be A+, but it becomes EX for the young version of Moriarty because it enables him to lay out his conspiracy without trying.
- Panic Cut (C+ Rank): A Skill similar to Disengage. No matter how confusing a situation gets, he is able to devise a plan B. It blocks mental disturbance debuffs.
- Mathematical Thinking (A Rank): Through precise calculations, he can always make the best decisions in combat. "What? Combat? Why would I ever fight anyone?"
- Slide Rule Weapon (B++ Rank): The slide rule in his hands is no mere ruler. It's a multi-weapon, capable of morphing into any weapon. "Excuse me? Who did this to my ruler and why?"
- Dice Selection (EX Rank): In his future, Moriarty will be pressed to make the choice of his life. Will he become evil or live the path of mathematics? He lived up to that moment calculating everything, but this one decision was the only one he left up to a dice roll. The result:
Moriarty Ruler was not originally planned to appear, and was only created because Takashi Takeuchi said he wanted to see a young Moriarty. The reveal of Holmes' origins was planned to happen in Lostbelt 7. At first none of the writers knew where they would put Moriarty Ruler, until it was decided to include him as the true boss who defeats Holmes, and so he was added to Lostbelt 6.5.