This peice is absolutely amazing. I love the use of colour and light balance here. The more I look at it, the more detail I see and just how much is there absolutely blows my mind. Great work on this peice, I sincerely mean it. My favourite part is Zabimaru, who I don't think has ever looked better!
An area that don't think work as well as the rest of the image is the spirit energy at the bottom. Because of the intense detail everywhere else, this appears out of place. What might work to correct that would be a more blurred edging.
Really, when it comes to it, that's fairly small. I applaud your work on this. It's obvious that you put a lot of effort and love into this peice.