There's a user in the category. It doesn't belong there. It should be removed. Page is only for bosses; it doesn't matter if they created all the pages or even the wiki itself, they should not be there.
I attempted to remove him, while adding the Collector to the list of bosses; for some reason, when I edited his userpage, I couldn't save changes. (It's worth noting that his only edits are a few edits to bosses' pages.)