@Shark It's not hard to not believe in something that doesn't exist; https://www.gnu.org/philosophy/not-ipr.html

You drew it - from a legal standpoint - it being a derivative work of a previous character is the issue.

Why not ask moon for permission to distribute non-proprietary derivative works of his works of such character? - he'll probably say yes and you'll be able to license it under a free license or release it to the public domain.