Polaris Hilda

Polaris Hilda (ポラリスのヒルダ, Porarisu no Hiruda) is a beautiful young woman, who acts as Odin's representative on Earth and the priestess of Asgard (similar to Athena's Pope). She is the main antagonist in the Asgard Arc and a supporting character in the Poseidon Arc and in Saint Seiya: Soul of Gold.

Asgard saga
She is possessed by the Nibelungen Ring (controlled by Poseidon) after rejecting his influence, and sets her sights on world domination in the name of Odin. Her younger sister Freya contacts Saori, and ask her and the Saints for help. Saori quickly sets up a strategy: she will take Hilda's place temporarily as priestess to avoid the melting of the Polar Ice, while the Bronze Saints fight Hilda's Guardians to reach her. Hilda is finally liberated after fighting Seiya, who awakened the Odin God Robe and the legendary sword Balmung with all Odin Sapphires, removing the ring, after which she returns to her gentle self. It's also revealed that Poseidon locked her spirit away in the Nibelung Ring as her body was controlled by him, torturing her psychologically since she could only watch her warriors die one by one.

Soul of Gold series
It is revealed that sometime after the Asgard Arc Hilda became suddenly ill and Andreas was place in charge until she got better. However, Andreas brought Yggdrasil to Asgard which Hilda knew he was trying to make the evil fruit. When she confronted him on this information he had the guard keep an eye on her to ensure she could not interfere in his plans. Knowing she is still to weak from her illness she entrusted the mission of stopping Andreas to Lyfia.

Trivia

 * Hilda's character is based on the Norse Valkyrie Brynhildr/Brunhilda, the main character of the Volsunga saga, and a major character in Richard Wagner's Ring Cycle. A daughter of Odin, Brynhildr serves as a Valkyrie for her father until she directly disobeys him. For her act, Odin sentences her to become human and to love the first man she sees, but through appeal, Brynhildr softens the sentence. Odin agrees to let her sleep full armed behind a fire barrier, as Brynhildr knew only a brave hero would find her, allowing her to fall in love with a courageous man. Her wish is fulfilled when she is rescued by the hero Sigurd (Siegfried in the opera), but their love is quickly doomed when Siegfried gives Brynhildr the cursed Nibelungen Ring without knowing of its deadly power. Through trickery, they are separated and in retaliation, not knowing Siegfried was innocent of the deception, Brynhildr goads his brother-in-law into killing the hero. She later regrets her action and rides into Siegfried's funeral pyre to be with him, taking the cursed ring with her.