Polydeuces was son of Tyndareus, King of Sparta and his wife Leda. Castor was his twin brother. Their sisters included Clytemnestra and Helen. Zeus was said to be the real father of Pollux and Helen.
The two brothers became famous adventurers, most notably serving with the Argonauts. However a feud with rival twins Lynceus and Idas resulted in the deaths of all four of them. Zeus offered Polydeuces a chance at immortality, effectively becoming a God. He opted to share it with Castor. The two share each other's fate, constantly alternating between Olympus and the Underworld. As deities they were patron to sailors, helping guide ships to safety. They are representewd in the constelation Gemini.
Polydeuces is the persona of Akihiko Sanada.