Your marker work is just a tad messy in some areas, I can see the grey of the ground overlapping the legs, but that's nitpicking.
The eyes may be a little overboard, but they look really cool! Great use of the markers there!
I wouldn't say that, I think it's just a good excuse to practice drawing backgrounds!
You had the right idea with the angle of the ground, it cuts through the line of action in Pohatu quite nicely. The only real issue I see is the rocks, they're pulled in way too close to Pohatu, but it's nothing practice can't fix!
Overall, this is really nice work!