Tōma was the brother of Eagle Marin and in the childhood, they were spaced from each other.
Tōma was arrested in a Olympic jail because of a mysterious crime, and Calisto in exchange to kill Seiya, because with this redemption of killing a enemy of Olympus, he will be forgiven.
Overture (Fifth Movie)
Tōma in that movie doesn't loves Marin like she loves him. But, he kept the bell of their childhood with him. So, in this movie, he doesn't have a cursed mask on his face (he has a mask, but is part of his Glory), and only served Artemis because he loves her; he did not accept Marin's position and try fight against her; but, in the final, he repents and protects Athena and Seiya of Artemis' arrow with his own body. After, he reconciles with Marin. His glory is the Icarus Glory.
In this manga, Tōma is more weak than in the movie, and his glory has a unknown name; because of the crime, he lost one of his two wings, so, he doesn't fly anymore. He was imprisioned and his mask will smash his head if Calisto or another Olympian god wants. Calisto doesn't free him (doesn't remove his mask) and orders him to kill Seiya. He refuses, but Calisto threathens kill him, so, he goes to kill Seiya, to get full freedom (in exchange for killing Seiya, Calisto will forgive him) to search for his sister with no problem. So, in Next Dimension, he doesn't love Artemis and always like his sister.
Marin and Hyoga protects Seiya (Hyoga freezes Tōma's arm), and Tōma follows Hyoga until Rosan (he wants revenge. He think Seiya will not leave the place where he is, so, he will kill Seiya later) and rebukes Shiryu because he give up to help his friend (Seiya). He goes to Olypus and fights against Hyoga again, but he uses his Kalisto to stop the moves of Tōma and goes with Shiryu to the past.