First, I want to say I know it's hard to get Hussie's permission to sell 3D items but the quality of your work speaks for itself. If you haven't considered already, I highly suggest you consider getting permission so you can start marketing your sculptures and charms.
That aside I want to express that I am not a sculptor. I can't work with clay to save my life so I apologize in advance if my critique doesn't make much sense.
One thing I love about your work is the unique face structure. It's very realistic without being too flat. The point of the nose kills me every time (in a good way). One problem I do have with it is the lack of detail in the ears. It's a small, nit-picking detail but I find it takes me out of the fantasy not seeing enough detail. But I do appreciate the flush in the tips of his ears.
Your body proportions are spot on. I love how you captured the bulkiness of his sweater without him looking unnaturally large. Especially in the transition from sweater cuff to hand. Those delicate little fingers are lovely but I again think it could benefit from a little detail in the knuckles (maybe it's there and I just can't see it). I'm also curious why you opted against nails? Still, it's beautifully sized, the arm crossing is spot on, I just love it.
I also particularly love the lean to Kankri's body. He's got that pose and natural expression to his face that says "I know better than you and god damn it you're going to listen". I adore Kankri's character because he reminds me a lot of myself, and being able to see it in this light just makes these little considerations so perfect.
A few words on the sweater. I love the curve of the turtle neck and how the shirt almost pools at the bottom but there really isn't enough texture in the sweater for me. Because you used such a high gloss (which I also think is just not a good idea) it shows every imperfection in your work. It's hard to get that level of smoothness in anything, I've learned the hard way, but you don't do yourself any favors by pointing it out with the gloss. I think a semi-gloss or more preferably a satin finish could have done wonders for showing off the quality of your work instead of distracting from it.
I also have to say I'm not keen on the hair. I'm amazing you got such a difficult style the way you did but I feel that when sculpting in sections like and layering the chunks of hair down they look like just that: chunks. It's like seeing a wig that's hair sprayed to spike out in glob sections instead of fanning out. Now, I know that the smaller you go with small details the more likely it is to break, but even a little more texture or smaller pieces layed in with the large chunks could have given a more realistic appearance and taken this to the next level.
Other than that the stand is perfect, the size is perfect, the colors are perfect, I think you did a wonderful job and I can't wait to see more of this down the road. I can guarantee you I'll be the first one to contact you about a potential art trade when you opt to open up trades again. As a 3D crafter I know the pain of shipping items like this and investing the amount of time you do in your work and I can promise I would do my utmost to make it worth your time.
Until then I'm so excited to see more of your work.