I really like the negative space at the top of this image Louison. I can only suggest that you dodge out the left left edge that goes out of frame and possibly the right and bottom too. This might add a floating feeling to your subject while still eluding to a grounded sense because of the the top blackness.
I like the lighting, but composition is a bit off.. too much black space at top.
Thanks so much for the comment. I did mean to have this much negative space, though. Photography is so subjective, not everyone can like everything. That's part of its beauty.