Most of the 'spirits' of this realm build cults of personality around themselves, based primarily on power. Manticore has a great deal of it, of course, but I could see expanding his power as a point of intimidation towards other spirits of similar or greater power. Holding a reliable and always open pathway between the spirit realm and this would be a boost to any spirit's power or fame.

My cats and I noticed the same when we poked through the shipping documents and crates, although I didn't catch the significance of origin at the time. The site of the Ring is also a sight of great spiritual power, although I haven't gotten a chance to poke around for myself.