Can I create [insert fan-created concept that uses KOL intellectual property here]?
Jick and Mr. Skullhead’s typical answer is “Sure, as long as you don’t try to make any money off of it. And if you do try to make money off of it, please ask us first and give us some of it if you do.” All the standard rules of intellectual property law apply to the KOL content, and if you’re not sure, asking first is a good idea.