Looks very intriguing.
I would almost suggest pushing the design elements some more.
Right now Hakumen looks... level 70 Burning Crusade.
Give him Uber Epic Tier 15 armour with extra stuff and spikes, and plates, and awesomeness. Chains, and belts, and the works.
Try to incorperate that Rhinocerous motif a little more. The horn on his head, and the horns on his shoulderpad look SO badass.
Maybe some oversized kneepads with tusks coming from it, with maybe another one on the belt.
Overall it's looking badass, and we know it's going to kick major ass.! but I think you can push the design some more. (Even if you do a quick paint over of your current mesh).