Thread:Wingstrike/@comment-26466194-20160725110710/@comment-3542404-20160725130111

"Crossovers from other universes and games are heavily frowned upon. This means that we don't want to see your Mario Chief combating SOLDIERS controlled by Sovereign alongside Tifa Lockheart and Rayman. If you absolutely have to, have to, must make a crossover, please do so on your user name space, where it will not be deemed a rule-breaker. However, there will be exceptions if the user will gain permission. The same goes for any directly-imported technology, species, ships, and characters from other games. Using a picture of one of these items to illustrate an original Gundam-related concept is acceptable, but directly copying said item from the game is grounds for an NCF and/or Rule Breaker template."

- Gundam Fanon:Rules

Short version: You can't directly take HN material and use it, but pages inspired by it is ok.