Board Thread:General Discussion/@comment-3542839-20140227002012/@comment-5471249-20140516005349

Oh, before I forget... I found more evidence for my theory... In The Lost Hero, Hera states that the Seven "must be the  seven greatest demigods of the age "... As a son of one of the Big Three, Nico is an extremely powerful demigod, and even Jason is afraid of him, and admits to being less powerful... Hence, Nico clearly is one of the "greatest of the age", and not including him in the Prophecy would not make sense.