Hey Jorge, really cool illustration. On first glance I would say he's some kind of dark unicorn knight? ^^ I especially like the way he looks at the viewer and the relaxed but cool pose.
However to me he looks just slightly offbalanced and almost a bit like he's floating or standing on his toes. That's probably because his front leg is slightly longer than the other one, and the perspective of the foots?
Another thing I would try to avoid is having his one hand hidden behind his waist. Usually that says somehing like "I'm too lazy to draw the other hand" or something like that ^^. Could be way more dynamic with the other hand shown.
Apart from that I really like it. Nice job!
