As far as my knowledge is concerned, I know about the Ghost World as a special skill of a person or a curse of a demon or something. There are, in rare cases like this one, an artifact that can create a ghost world as well.
But a trial? Now that is something that I have never heard about. Most people chose to just kill themselves in the Ghost world, and then travel back to the main city by reviving after the penalty of 36 Hours.
Even those who tried to understand the Ghost world, didn't make much of it, except once where a guy happened to luckily kill the owner of the Ghost world and escaping from hit. He didn't gain anything from the Ghost world though.
