User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-97.120.151.225-20121221100917

Could the 'world' falling mean Gaia? She is an earth goddess. It would make the prophecy right regardless of who won. It might also give a hint of the sacrifice that is used to stop/revive Gaia. They could mean any of Percy, Leo or, Jason depending on how you look at it.