User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-3146930-20130611215552/@comment-6064271-20130613000759

if its about 7 halfbloods then you must be talking about the prophecy of 7 but that had nothing to do with swearing on the river styx, is this the one you talking about?:

Seven half-bloods shall answer the call.

To storm or fire, the world must fall.

An oath to keep with a final breath,

And foes bear arms to the Doors of Death.