Eileen is a friendly NPC that is encountered throughout Bloodborne. She is first met in Yharnam and will greet the player upon talking to her. She explains her role as a Hunter of Hunters, that ''there are no humans left'', and that the player should go and continue hunting the beasts that roam the town. The first encounter will reward players with the 'Shake off Cape' gesture and 2 Bold Hunter's Mark.
The second encounter is outside the Cathedral Ward HUB after Vicar Amelia has been killed. There she will notify the player of a crazed Hunter by the name of Henryk whom is currently hanging around the Tomb of Odeon. She warns the player not to get involved and that he is her latest prey. Upon heading to the tomb this will then trigger a fight with Henryk; Eileen will shortly arrive once the fight has begun to provide assistance. Eileen can die during this fight, though she has a rather significant amount of health. Once beat Eileen will thank the player for their assistance and will reward them with the 'Approval' gesture.
Eileen's final appearance is outside the Grand Cathedral. She is shown to be badly beaten and bloodied, noting that her current target has gotten the best of her. Despite urging the player not to fight him, players must ultimately kill the target to finish Eileen's questline. Once killed Eileen will reward players with the Crow badge and the Hunter of Hunters rune before passing away from her wounds. The Crow Badge will add Eileen's Crowfeather outfit and her Blades of Mercy weapon to the store. The rune will slightly hasten the player's stamina recovery.
Should Eileen have been ignored/missed throughout her earlier appearances, then when heading to the Grand Cathedral after Rom has been killed Eileen will be encountered as a hostile NPC. Driven insane, likely by the plague, Eileen believes that killing all Hunters will put an end to the nightmare and attacks the player immediately. She is equipped with her Blades of Mercy and will often throw Throwing Knives at the player. Whence killed she will drop her Crow Badge.
- Eileen will show up outside the Cathedral Ward even if players happened to miss her first appearance. However when first speaking to her she will introduce herself as like in the first location she appears; once her dialogue has been exhausted talking to her again after leaving and then returning to the area will initiate the Henryk phase of her quest line.
- Eileen's outfit includes a plague mask, which were worn by a separate contingent of doctors from regular practitioners during the seventeenth and eighteenth centuries. The beak of the mask was used to house incense and herbs so as to help the doctor stave from potentially catching the plague. In Eileen's case this is likely so as to also help fight away the plague that has gripped Yharnam, driving people insane and turning them into beasts.