The spirit Tatara made a contract with. Corti, as Phoron calls her, is one of the eldest spirits in their world, having six wings and called the Red Elder Spirit —as well as other titles such as Crimson Annihilator or Bloody Duchess. She is entranced by young Phoron's singing voice and thus decides to make a pact with him so he will be hers only.
Most of the time, Corti has the appearance of a child. She has a selfish character and dislikes it when Phoron is being kind to other girls.