Helena

Helena is a member of the Mythos Cyborgs and an antagonist in the "Mythos" arc of the Cyborg 009.

History
Helena first encountered 009 after he fought off one of the Centaurs. She attacked him with her Trojan Horse mecha, but 009 managed to defeat it by destroying its head and computer system. Before Helena could be consumed by the horse's explosion, 009 took her to safety.

Helena later witnessed Apollo defeating 009 and saved the cyborg after he fell into the ocean, as return for him saving her, and vowed to reunite him with his team.

When Atlas attacked the 00 Cyborgs, Helena lied and told him that the 00 Cyborgs had equipped her with a bomb, causing him to stop and let the cyborgs go on the condition that they return to Magma Island in one hour and return Helena.

Helena was eventually convinced by 004 that Black Ghost was the true enemy and that she should cooperate with them. However, Atlas soon resumed his attack, angered that Helena had not been returned, but 001 used his psychic powers to teleport the submarine away.

After 007 and Dr. Uranus met up with the team, Woman Esper began using her psychic powers to attack them, prompting Cyborg 001 to go back to it to confront Woman Esper, with Helena accompanying him.

At the end of the arc, during 009 and Apollo's rematch, Helena through herself into the battle and tackled her brother to prevent him from killing 009, causing both of them to become immolated.

Cyborg 009: Monster Wars
Helena appears in the 1967 movie as a spy for Black Ghost sent to infiltrate the 00 Cyborgs and the holder of the title of "Cyborg 0010". She later turns good after being saved from falling to her death by 009 and assists him in rescuing his companions, though she winds up being executed by the Black Ghost Leader for her defection.