Saint Seiya: The Heated Battle of the Gods (1988)

In Siberia, Hyōga saves a man that is being attacked. Injured, the man manages only to say something about Asgard. Some days later, Saori, Seiya, Shiryū and Shun are wondering about Hyōga and decide to go to Asgard to investigate. At Valhalla, the Lord of Asgard, Dolbar, says he has not heard of any Hyōga and neither has his right hand, Loki. However, at all times Seiya and the others can feel an evil cosmo emanating from Loki and the other Odin Saints called God Warriors. Shiryū, in particular, notices a familiar cosmo coming from Midgard, a mysterious, masked God Warrior. Dolbar makes it clear that he is trying to take control of both Asgard and the Sanctuary, imprisoning Athena in a strange dimension within the giant statue of Odin. Midgard reveals himself as Hyōga and tries to kill Shiryū to prove himself to Dolbar. Thus, it is the task of the Bronze Saints to defeat Dolbar, Loki and the rest of the God Warriors, to save Athena and Hyōga.

Unfortunately the movie Saint Seiya: The Heated Battle of the Gods is not yet available on HBO Max.