I am going through some older things I had marked down to investigate. The fan fiction about "Mateo Story" seems to be the same as what you've added to The idea Wiki, so I'm going to delete it.
In general, it's okay to create fan fiction as long as you say it's fan fiction. If you don't say it and you add it to a wiki like this where we're trying to stick with the facts about the subject, it kind of becomes lying. This isn't said to be mean about it. Just letting you know that a lot of wikis want to keep fan fiction separate from facts, or at least clearly identified.