Knight Master Isolet is one of the founders of the Grand Chase, who recruits Elesis, Lire, and Arme to their guild. She is the guardian of the kingdom of Serdin. As the quest NPC for the Serdin region, the Knight Master is only seen in dialogue of Serdin's dungeons. She gives missions to the trio until they reach Gorgos' Dungeon, where she sends them off to find Kaze'aze and wishes them luck. Speaking to Lass, she does not judge him by his past and does not hold him responsible for his actions while possessed, instead giving him a chance to start over.