During the Quests, the player begins to hear rumors about a man with holy powers, capable of healing people from malfestation.
Later, in a forest full of malfesteds, Estes will fight the player, mistaking him for one of the monsters. After accompanying the player in a fight, Estes reveals he is the man who can heal malfestation doing so in a malfested who was about to be killed.
He also assists in the fights against the High Priest of the Fygul Cestemus, Giuseppe, and a Golem sent by him. Its later revealed that Estes actually is a creation of the Fygul Cestemus, made with alchemy as a template for the creation of various other warriors.
It becomes clear later, that healing the malfested weakens Estes, though he refuses to admit it. Giuseppe constantly attempts to capture Estes, but is eventually killed by the player. Estes, after being severely weakened, uses his remaining strenght to open the Astral Gate for the player and dies. The player, then, protects his corpse from an attacking Elysium and its soldiers.