Quick recap
In the 18th century, Tenma is an orphan from an Italian village who becomes the Pegasus Bronze Saint. His best friend Alone, a gentle boy who is always painting, learns that he is the body Hades has chosen. Alone's sister Sasha is reborn as Athena and gathers her Saints for a new Holy War against the 108 Specters. Tenma fights to bring his friend back, even as Alone changes with every meeting. That generation's Gold Saints step in one by one, and several fall along the way. Hades starts painting the Lost Canvas across the sky, a picture that dooms the whole Earth. The anime stops in the middle of the war: the adaptation was never finished.
