In Season 6, Halwyn is a hellhound who slept dormant for a hundred years in Eichen House. He was who was behind the construction of the closed unit of the facility. Halwyn awakens from his slumber after the Anuk-Ite was released from the Wild Hunt, seeking to hunt down the entity and destroy it. He gets into a brawl with Deputy Jordan Parrish and Liam Dunbar mistakenly concluding Liam is a host of the Anuk-Ite. After being clawed and weakened by Liam, Halwyn is hunted then killed by Tamora Monroe, but his amortal spirit contacts Lydia Martin from beyond the grave.