While tactically sound, it is important to remember cover only works if you are behind it or in it, not in front of it, as Guardsman Gregory on the ground there will attest.
--------------------
Nice one dude! Looks like you took all the feedback notes into consideration, and the piece turned out stellar!
The dark city in the top right with the crosshatching matching up with the spread of the explosion was really well done, and the characters look well armored and articulated, so a very faithful rendition!
Only real zone that looks semi-rushed is the building with the skulls in the top left, as the shading gets a little long and scribbly compared to the foreground characters and elements.
It wouldn't be as big an issue if the building details weren't so large, so it stands out.
Aesthetically and overall the piece works, but I wouldn't be doing my job as 'Art Advice Buddy' if I didn't point it out. :P
Keep up the great work my dude!