Helena is one of the antagonists in the Mega-CD video game adaptation of Cyborg 009.
As with the incarnations of Helena seen in Cyborg 009 Monster Wars and the SF Roman light novel, her storyline and role are merged with that of Helen. The plot surrounding her is a merger of the Mythos and Yomi arcs in turn, with some details from Assassins.
True to her classic appearance, Helena has short, spiked-up blonde hair and a jeweled tiara. As with her Monster Wars design and how she appeared in some panels of the manga, her tiara has a single red gem in the center.
She has no sclerae or pupils in her eyes, which are a deep blue shade and have a sparkly appearance.
In her civilian guise, Helena is first seen wearing a sleeveless blue dress, and later wears a red qipao while staying at Dr. Gilmore's. After unveiling her true identity and purpose, she wears a long white gown and cloak, and gold wristbands.
Helena is later revealed to be part of a set of triplets, with her two other nameless sisters dressing in the exact same manner.
Initially, Helena appears to be an innocent, somewhat amnesiac young woman, but her duplicity is soon discovered, with her attempting to mercilessly kill 003/Francoise on orders of Black Ghost, with the intent to take out the other cyborgs afterwards.
She grows close to Joe/009 after he battles her, and holds strong feelings for him. Even so, she realizes the feelings that Francoise had for him and later apologizes to her for all the trouble she caused, but adds "You were jealous of me. Farewell." just before she's shot to death.
Helena has no particular special abilities witnessed, other than a ring she uses to summon her Trojan Horse.In the boss fight where Joe battled against her, she used the giant Trojan Horse mecha to attack with. The mecha was armed with lasers and could configure into different modes for flight or attack, but it was destroyed by Joe's Super Gun attacks.
In her assassination attempt on Francoise, a bracelet she wore was revealed to contain a wire that she planned to use to either strangle or decapitate her with.
After Joe and Francoise were heading back from one of Francoise's ballet recitals in Paris, they happened upon a mysterious young woman who appeared in front of their car and was hit. She could only mutter the words "Black Ghost" before passing out, causing the two cyborgs to realize that the Black Ghost organization had been revived.
The girl was brought back to Dr. Gilmore's headquarters, where she introduced herself as "Helena Tomoshi" and informed Joe of Black Ghost activity in a mansion out in Tokyo. While he was distracted fighting Cyborg 0012, Helena plotted to kill Francoise but was stopped by his timely return. Helena confessed that she was being manipulated by Black Ghost and sent as their spy, but remained cryptic.
While the other cyborgs did not trust in Helena, Joe was still willing to believe her innocence. However, Helena escaped, and Joe had to go track her down, fighting the Cyborg 0010 twins before battling her in her Trojan Horse mecha. The rest of the 00 cyborg team still did not trust Helena, but soon learned Francoise 003 had been abducted by Skull and taken to an underground kingdom in Greece.
After Joe defeated the rest of the Mythos cyborgs, he and Helena learned that Skull's subordinate Van Vogt was holding Francoise and Helena's two identical sisters hostage. Helena was forced to give herself up to Van Vogt, and was shot for her betrayal, along with her sisters. While Joe managed to shoot and kill Van Vogt, he was too late to save Helena. In her dying moment, Helena confessed that she was happy for the short time they had together, and that she was confident he would be able to defeat Black Ghost.
During the final fight against Skull, a vision of Helena appeared to Joe, along with visions of Francoise and his own mother, which gave him the strength to continue fighting.
- While it could be assumed that Apollo may be this Helena's brother (as he is in the manga, and his counterpart in SF Roman), there is no express confirmation or acknowledgment either way by her, as Apollo's role is brief and mainly just a level boss for Joe to fight. It is also not clarified whether or not she is a cyborg or a regular human, and the extended backstory of the Pu'Awak species also does not come into play so the nature of her sisters and whether or not they would have the sibling telepathy would also be ambiguous.
- Due to Joe and Helena taking focus in the plot of the game, Helena can also be seen as standing in for Vena to some extent, as the subplot with Albert in the Yomi arc was entirely excised and Joe takes up his role in killing Van Vogt as vengeance.
- The removal of the Zattan also creates some ambiguity in Helena's (partial) mindwiping, though it could be assumed that Skull or Van Vogt were responsible.