Season 1 of Saint Seiya: The Hades Chapter premiered on Nov 09, 2002
Hades is planning to take over the world, to achieve that goal, he sends out deceased Gold Saints to take Athena's head. Seiya and the other Bronze Saints come to help but their help isn't appreciated by the remaining Gold Saints that are still alive.
Season 2 of Saint Seiya: The Hades Chapter premiered on Dec 17, 2005
Seiya and the rest of the Bronze and Gold Saints who have survived the Sanctuary battle have entered the world of the Dead. They are fighting to get to Hades and defeat him.
Season 3 of Saint Seiya: The Hades Chapter premiered on Dec 15, 2006
Season 4 of Saint Seiya: The Hades Chapter premiered on Mar 07, 2008
After the 12 Gold Saints sacrifice their lives to destroy the Wailing Wall, The Bronze Saints enter the deepest realm of the Underworld, Elysion, where they face off aganist Hades's two most powerful servants: The Twin Gods, Hypnos and Thanatos, before they can reach Hades for the final battle.