Sedna was the daughter of the Inua Sky Father Hodiak and the primordial Earth Mother Gaea, Sedna was once a beautiful goddess who spurned all who sought her hand in marriage. However, she eventually became enthralled by the song of a stranger who promised her a luxurious live in his distant kingdom across the sea. Sedna ventured to her mysterious suitor's homeland, only to discover that he was a humanoid avian who lived in squalor and used his songs to deceive her. Hodiak eventually relented to Sedna's desperate pleas for salvation and slew his daughter's captor, but abandoned Sedna when the murdered suitor's countrymen came to avenge his death. Angered at her father for his abandonment of her, the wrathful Sedna attacked him. In retaliation, Hodiak cursed his daughter and banished her to the northern seas' icy depths, where she was regulated to a lonely existence serving as the goddess of the dead.
In modern times, Sedna located the wreckage of a sunken ship once commanded by Asgardian thunder god Thor. Using jewels obtained form the ship's wooden figurehead, she tracked down Thor in New York City and intended to make him her consort by force. However, before Sedna could use her magic to transform Thor into a suitable mate, he was rescued by Namor the Sub-Mariner, who has clashed with Sedna decades earlier. Weakened by the warm ocean waters, Sedna gave up her pursuit and retreated.