Only real people should go in this category, no fictional characters.
Current Arbital policy states that no unflattering facts may be listed about living or recently living human beings, since Arbital currently has no process in place for deciding when it's okay to cite sufficiently verified facts on a person's page that this person would prefer not to be listed. As an exception to this rule, linking to a person's Wikipedia page is acceptable (even though Wikipedia's process here ain't that great either), and this is how you should handle it if you need to cite relevant facts about e.g. Vladimir Putin.
Arbital has no notability policy, but during this stage we prefer to add listings for people only as facts about those people become naturally relevant to other Arbital articles.