Saber (Fate/Grand Order - Fergus)

(フェルグス・マック・ロイ) was the former king of and foster-father of Cú Chulainn in the.

Background
Fergus mac Róich was the king of until being tricked out of his throne by. He was also a knight of the who took brought Cú Chulainn from his mother  to serve as a soldier for Ulster. Later after Cú Chulainn returned from the land of shadows, Conchobar had Fergus' sons killed "out of lust for young women", causing Fergus to defect to Unlster's enemy. Spurring on queen Medb of Connacht out of hatred for Conchobar, they went to war with Ulster, where he managed to corner Conchobar during the decisive battle. Fergus was prevented from killing Conchobar, and was said to have redirected his rage over it upon three hills, using Caladbolg to blast the tops cleanly off them.

Fate/hollow ataraxia
Medb is mentioned in Lancer's flashback.

Abilities
Fergus was said to be the pride of the Red Branch Knights. He weilded the sword Caladbolg, said to be Cú Chulainn's natural enemy.