Mortlach is a Holy Knight serving King Arthur Pendragon of Camelot in the sequel to the Seven Deadly Sins series. He is a tall, slim man with long, wavy ash-blond hair and large, expressive light blue eyes. Mortlach is driven by a deep personal motive: his nephew Diodora, the son of Percival’s father Ironside, suffers from a poisoning that can only be kept in check by the protective environment of Camelot. Mortlach believes that the Four Knights of the Apocalypse are a threat to Arthur’s eternal kingdom and, by extension, to Diodora’s only chance of survival. This makes him fiercely hostile toward Percival and his companions.

Mortlach leads a group of independent Holy Knights tasked with tracking down the Four Knights. He confronts Percival at the entrance to the Demon Realm, where he reveals that Percival is actually a Life Spirit, a revelation that shocks Percival into a coma. Mortlach’s actions provoke Lancelot, who slits his throat, killing him. His death removes an obstacle for the protagonists but also deepens the emotional stakes surrounding Percival’s true nature.

As a Holy Knight of Camelot, Mortlach is a capable combatant, though his specific magical abilities are not detailed in the available information. His relationships include his loyalty to Arthur, his bond with his nephew Diodora, and his connection to Ironside, who appears to be his brother. Mortlach’s role in the story is that of a determined antagonist whose personal tragedy makes him more complex than a simple villain. His demise marks a significant moment in Percival’s journey and underscores the lengths to which Camelot’s knights will go to protect their kingdom.