Board Thread:Naruto Discussions/@comment-24593592-20140716142357

Kaguya as the Gedo Mazo was an outer path summoning and could rip out souls just like the King of Hell. Now if you look on The King of Hell's wiki page he is based on Yama, who was part of a race called the Devas last lived in the God Realm. These Devas happened to be at war with another race known as the Auras.

I believe that Kishi is trying to do what he did with the Legend of Jiraiya and adapt the six realm concept into his series. Rikudo Sennin also translates into Six Realm Sage. What do you think? 