One thing I think I'd like to see is a completely redone facial structure. What's really killing this for me is the fact that the "overlord" has the facial structure of a human.
I don't know if this is a possibility - you seem to like the design - maybe just me being nitpicky.
Thumbnail wise - the one where he's coming up through the floor and he's lit from below - Love it!
Doctors heal you, Artists immortalize you.
"Those who can, do. Those who can't, teach" - bullshit.
The usual staples for anatomy: