Is Fan-work Ethical?
Fair use is hard to achieve actually (few references to source material but almost everything needs to be original). Even if you do not make profit, fan work is illegal from these examples: Japanese Youtuber sentenced to prison for uploading fan footage. Hasbro shutting down a non-profit fan game based on My Little Pony. Nintendo sending DCMA over fan made Steam icons. Blizzard shutting down non profit fan server of vanilla World of Warcraft. Fan work is not protected by law. It is not legal. You are always at the mercy of the owner of IP. Most owners allow it, some really hate it and will sue you at any chance they get.