Oh, pshh. [He waves a six-fingered hand.] The only qualification you really need for an exorcism is a nearby ghost--

[Hey that sure is a real loud noise. Was that the Spiritomb or the recently-freed 108th spirit? Yikes. If even the Duskull is scared of it that sure isn't promising.]

Anyway. Bookstores. I hope you found something of use because you may need to exorcise that spirit properly if you can't get it back in the keystone.