I TOTALLY AGREE! Oni-sama gets NO ATTENTION! And he is my FAVORITE! I am so glad someone other than me is out there paying homage to him!
I don't know much about "Art Nouveau" (I am assuming that is the style you used), however, I am very pleased to see that the content of your style is accurate and faithful towards the originals to a surprising degree. Clean lines and well maintained focus on the important areas also give you points. From my perspective, this is a 5/5.