Alpha Dubhe Siegfried serves as a God Warrior of Asgard under Polaris Hilda, Odin's representative on Earth. He is identified as a descendant or reincarnation of the legendary Norse hero Siegfried, slayer of the dragon Fafnir. This lineage grants him near-complete invulnerability, mirroring his ancestor's trait, but also inherits the same vulnerability: a mortal spot over his heart where a leaf prevented Fafnir's blood from touching during his ritual bath. Trained in Asgard, Siegfried developed deep loyalty to Hilda during her benevolent rule, secretly harboring affection for her. He vowed to protect her life, a commitment he maintained even after the Nibelungen Ring corrupted her personality. Despite warnings from Freya about Hilda's unnatural changes, Siegfried dismissed these concerns, attributing her aggression to her own will and choosing unwavering fidelity over intervention. As the leader and strongest God Warrior, Siegfried commanded his comrades during Asgard's conflict with Athena's Saints. He confronted the Bronze Saints at Odin's statue as their final obstacle. Demonstrating superior combat prowess, he defeated Pegasus Seiya, Phoenix Ikki, Andromeda Shun, and Cygnus Hyoga using techniques like the Odin Sword, which traps opponents in a cosmic-energy barrier before unleashing destructive force from below. His ultimate technique, Dragon Bravest Blizzard, channels freezing cosmic energy into a two-headed dragon-shaped blast capable of freezing targets. Executing this move briefly exposes his chest vulnerability. During the battle, Dragon Shiryu discerned Siegfried's weakness and relayed it to Seiya. After sustaining damage to his heart spot from Seiya's attacks, Siegfried faced Siren Sorrento, a General of Poseidon. Sorrento revealed that Poseidon manipulated Hilda via the Nibelungen Ring, confirming the Saints' claims. Enraged, Siegfried attempted a suicidal attack against Sorrento, grabbing him and ascending skyward. Sorrento countered by inducing auditory hallucinations (or, in some accounts, rupturing Siegfried's eardrums with his flute), causing Siegfried to release him. Siegfried then transferred his Odin Sapphire to the Bronze Saints before perishing in the confrontation, sacrificing himself to aid their mission to free Hilda. In the spin-off *Saint Seiya: Soul of Gold*, Siegfried is referenced as the brother of Sigmund of Grani, another God Warrior. Surtr mentions that Sigmund's hatred for Athena's Saints stems from Siegfried's death during the Asgard conflict. Siegfried's God Robe embodies Fafnir's draconic form, reflecting the myth of the dwarf prince cursed into dragonhood. This design aligns with his ancestral connection to the Siegfried legend.