OK, so if the description that I used is not an actual legal standard then I guess I could put it another way. What I mean is that the assets that I attached are intended to be interpreted as fan art in relation to copyright, and I was curious about the legal implications in relation to non-commercial matters.
Let's explain a bit of the details, that will probably help you more.
First, copyright does not care if commercial or non-commercial.
The only difference would be the amunt of damages you'll be sued for - which is usually much higher for a commercial game while noncommercials can get away with a cease and desist and legal fees until they take down their work from distribution.
Second, the term you need to understand is shared copyright.
Taking any resource and editing it creates a shared copyright of both the editor and the original artist, and neither can use the result without licence from the other. So ripping a resource and editing it does NOT give you the right to use it.
A special form of shared copyright is if you do the work all on your own but follow the style or design of someone else. In that case the other artist can only hold the copyright on the design, but never on your own work.
And then it becomes a bit vague because you can claim accidental similarities unless you name it for the original, and if you can claim to only have been inspired by the original you are legal.
(or if you can claim parody, but that is not as easy as you think because your game needs to be laughing at the original and a few other requirements)
In the end any fanart is almost automatically illegal if it claims the name of the original without licence, but can be legal if it only claims to be "inspired by" and has detectable differences.