Piton was a assistant of the leader of army of Athena, and after, assumed the office.
Gigas always ordered to Piton helps him. Piton ordered various attacks, including, the alliance with the Caraib Ghost Saints.
Leader of the Army
When Gigas ran away and disappeared in Japan, Piton assumed his post, and he wanted it.
He sends Silver Saints to kill Seiya and the other bronze saints of Saori Kido, but after various fuels, Shaina was prohibited by him, to go to Japan, and never understand why Shaina wished to kill that bronze saints so much; he did not know Seiya saw the Shaina's face. The last mission gives to Shaina, was sending her to stop the air invasion of the Sanctuary, and she could choose two saints to follow her.
During the 12 Temples Battle, Piton tries with his servants, stop Marin and Shaina invasions, and Shaina defeats him and how he as the leader of the army (so, knows about invasion), he must know the passage to the pope's room, and was used to Shaina arrives there.