Question regarding MapleStory images (copyright)

So my advice is palette swap the images, and then alter them enough so that you can really say that they are no longer connected to Nexon/wizets stuff...

Note that this does not in fact magically make it yours/unique, it makes it a derivative work, and unauthorized derivative work is still copyright infringement unless you can prove fair use. The people who squeak by don't do it because it's legal - They do it because the company they're offending doesn't consider them a threat and doesn't feel like making an example of them. Nexon on the other hand has historically kept Lloyd Korn busy throwing out DMCA take downs and threats left and right, even on things that are clearly fair use, so ones that are clearly not should be doubly concerned. In the long run it's a lot easier to just find your own art work.