Mos-Quitoxe
To me, like a lot of people, it really just comes down to the typing. However, I don't think looking like the typing is nearly as important as making sure you are not mistaken for other types. While it might not be that obvious what type the Mos-Quitoxe's design is, it does not look particularly like any other typing either. Yilx's on the other hand just looks too much like a Dark type to me. It is a fantastic design, but when it comes down to two as good as these, I think making sure it doesn't look like the wrong typing is the most important thing.