I haven't here to check up on some of the newer stuff, but Ink, I think all of your work is amazing.
Sazed - awesome. I have nothing to suggest. In fact, I'd like to see a color rendition, if you find the time/interest to do so, just to see what your take on the color design on the robes would look like.
Mistwraith - Take 2 is better. I agree, maybe ditch the hair and cut down some of the skeletal stuffs (you've got a lot going on, which looks cool, I'm just not sure that's what the description was getting at). Also, and I can't back this up with any text, I kinda got the impression that their skin was transparent-ish and that the bones could be seen in their entirety. I'm probably just making that up, haha.
Vin - possibly the best Vin I've seen here, and there's some great competition. I love the oversized sword too, that's about how I imagined it from WoA.
Koloss - Freakin' scary dude. I love 'em. Yeah, I think you've got them pegged.
Again, great stuff!