Lol forgot my main point. legal/illegal doesn't matter. Erasing, changing or painting over another artists work in down right disrespectful and wrong.
I don't want to hear the argument that it was disrespectful of them to produce what you perceive to be a bad card in the first place because we aren't in first grade where we think two wrongs DO make a right. Go buy your own stock if you want to paint, or do you due diligence and get work on an official set if you feel your art belongs there instead.
"Principles only mean something if you stand beside them when it's inconvenient"