Single post in Sprite Permission Request Thread

I'm holding an art contest where users would submit their art for my use. It will feature my Pokesona, but I am also wondering if they are allowed to include melanistic Remoraid in their artworks? (like, for an extra character they want to add) Also, if I ended up evolving Remoraid into Octillery, same question? I wasn't sure if this is allowed or not.