It turns out Hades was behind the underworld invasion and was the one who reserected Madusa. After He sends his troops to find the wish seed so Palutana sends Pit to find it before Hades. But it turns out the wish seed is A fake and Hades used it to luar Pit to the gardean of the seed, The Pheonix. When Pit defeats the Pheonix it sends out A beckon out to the world telling them someone has the wish seed. After finding this out every in the one whole world starts fighting with eachother.