Cú Chulainn (クー・フーリン, Kū Fūrin), Class Name Caster (キャスター, Kyasutā), is a Caster-class Pseudo-Servant of Odin summoned by Ritsuka Fujimaru in the Grand Orders of Fate/Grand Order.
The Norse God Odin, having foreseen the plans of both Goetia and the Foreign God, used Cú Chulainn as a proxy to help him save the Human Order. Cú Chulainn was initially summoned to the Fuyuki Singularity as Lancer, but Odin granted him his Authority, transforming him into Caster and giving him some of Odin's abilities.
Avalon le Fae:Fairy Round Table Domain
Cú Chulainn reappears, calling himself Grímr the Wise. When Cú Chulainn returned to the Throne of Heroes after defeating Artoria Alter in the Fuyuki Singularity, Odin let him retain his memories of that summoning. He was then summoned into the English Lostbelt a year before Chaldea arrived there. Cú Chulainn spent the year waiting for Chaldea to arrive learning what he could about Odin's actions in the Lostbelt as Grímr 6,000 years ago, as he was not given that information when summoned.
When Mash loses her memory in the Nameless Forest, Cú Chulainn follows and watches over her in the form of a white wolf. He reveals himself when Morgan's army attacks Sheffield, turning back to his true form to fight off Fairy Knight Lancelot while Mash and Habetrot escape.After the survivors of Sheffield flee the city, Cú Chulainn - once again in his wolf form - accompanies Mash and Habetrot through the Vein Corridor to reach Norwich.
