Cassios

Cassios was practically the first enemy of the series Saint Seiya. He was to Seiya who struggled to get his Pegasus Cloth. Apprentice Shaina, Cassios wanted the Pegasus Cloth, and with his height and musculature, thought would get to win the tournament with physical force that all saints have. He reached the final of the tournament after decptar all challenges, and their final opponent would be Seiya, who as a child was always beaten by Cassios. Cassius decides to cut off the ear of Seiya, but Seiya cut his ear first. Seiya mocks Cassius for failing to develop Cosmo and so we always have the same physical strength; with the cosmos, Seiya overcomes the force of Cassios and defeat, leaving Shaina disappointed.

After the tournament
Cassios value your sensei, and loved to have made him a man. He never forgave himself for losing the tournament to Seiya, which in its design, made his sensei lose morale. He went to live as a soldier of the sanctuary, because once there, could not get out unless one could Cloth. Aiolia later, still taking care of Cassius body.

After know that Shaina was injured trying to protect Seiya, he accepted defeat (he was only ally of Shaina and had no connection with the Pope betrayed). Seiya invade the Lion Temple, and Cassios knew that Seiya would die if Shaina did not help again himin the fight against Aiolia, but he decided to protect Seiya he himself; thus, Shaina don't be sad about his death. Cassius commits suicide (hopeing Aiolia leave the mental control of the Pope), but does not. Seiya hits Aiolia, and Aiolia turns back to the normal.