Ophiuchus Shaina (Omega)

is a female Silver Saint of the Ophiuchus constellation, and long time comrade-in-arms of Sagittarius Seiya. She is also the mentor to Koga. Shaina can use the Thunder Cosmo.

In antipation Third Holy War
The threat of Mars (temporarily) removed, Shaina follows Saori in retirement on her island. During the thirteen years that followed, she devoted herself fully to the task of training the young Kōga as a Saint. This work was far from easy: her disciple indeed showed to be particularly recalcitrant, as he ignored the real ins and outs of such training and his role in the future history.

Mars attack
When Mars makes his return to Earth to kidnap Saori, Shaina comes to her aid but is quickly defeated by the god. She then assists Koga when he obtains the Cloth of Pegasus for the first time and transforms into a full saint. Kōga's efforts proved fruitless however and the latter left the scene of an explosion releasing Darkness,  Ophiuchus then protects her disciple from the blast and gains an injury of Darkness. The injury prevents the inflicted from igniting their Cosmos as it would spread to the whole body and kill them. Recovering, she leaves only Kōga to seek Saori, after making him promise he would not return as her mission is not complete.

Thunder Ruins
When Kōga and his companions arrived in sight of the thunder ruins, they meet Shaina who was waiting for them: his disciple had indeed contacted some time ago , because she was the only one of its allies have for element the Lightning , attribute needed to destroy the Heart of the Ruins. Before the group gets under way, Ophiuchus takes apart and his disciple, saying she feels now ready to know the truth, it reveals its origins as well as those of Aria .After the six Saints take the path of Ruins. They are taken successively ambushed by three Silver Saints, but they are held by different companions Kōga, and it can reach the main building with his master. They are expected by Eden, accompanied by Aria. Kōga while holding the son of Mars, Shaina  takes Aria to the Heart of Thunder and both join Cosmos to destroy it. Enraged by his failure, Eden is determined to end the Pegasus Saint, Aria then intervenes, causing the release of Darkness buried in Kōga. Shaina is the only person on the premises who manages to escape absorption by the Darkness.

New War
At the end of the war against Mars and Abzu, Shaina is cured of the darkness wound inflicted on her body, and is able to don the Ophuicus cloth once more. Some time later, when a new threat - personified by the goddess Pallas - looming, Shaina returns to the Sanctuary, and is appointed head of the guarding forces. She welcomes Kouga, who is accompanied by the Steel Saint Subaru, the latter acting misogynistic towards her. While her disciple goes on to meet with Athena, Subaru attempts to follow him, only to dragged back by Shaina whom effortlessly defeats him until she senses an unknown power within the boy. Before she can investigate this phenomenon, Kouga reappears from his meeting with Athena, heading for Paleastra with Subaru tagging behind, leaving Shaina concerned over the boy's future.

Gathering in Sanctuary
Shaina is present at the gathering of the Saints in the Sanctuary, a prelude to their entry into the war. It is she who is responsible for announcing the arrival of Athena's peers.

Battle Of Pallas Belda
Later, she took part in the Battle of Pallas Belda. It participates in the defense of an outpost alongside Ban, Nachi and Ichi, until the arrival of Kiki, which stood in the place to repair Cloths. When a new attack - led by Dione the Whip "Plasma Snake" and his men - occurs, it is the first to start the action. It was she who persuaded the master repairman to focus on the task of restoration and let his companions fighting load.

Pallas Castle Time Gate
Later, she is part of the Saints covering the back of Athena and its vanguard, allowing them to enter without delay into the Pallas Castle.

While the god of Time Saturn woke up and retired to his castle orbiting Earth after frozen almost all the inhabitants of the planet, Shaina is one of the last defenders of humanity struggling against enemy troops.

Final Wars Againts Saturn
Saturn uses the Chrono Eternal Conclusion that freezes the whole time the inhabitants of the Earth.When all seems lost, Athena gathers the Cosmo of all the other Saints to restore Kouga, who rises again as the Super Omega Saint, determined to stop the God of Time once and for all.

Epilogue
After Koga's clash against Saturn, peace is established as the humans begin to rebuild everything after the War.