First off, man, unbelievably well done, each character manages to stand out amongst the crowd while still lending their look/persona/style to the collective. Superb, sir.
That being said, I believe the lighting is a little too simple only (seemingly)having one source, making the bottom half of the crew looking dramatically lit, and the top half looking dramatically dark, with the exception of Pyron, who I think it would be great if he could serve as a second lighting source to the upper half, along with the flare from B.B Hood's gun.
And while it may be tough to find a good color to use as a backdrop for such a colorful cast, I find that the Pinkish-purple gradient blends in with the cast a bit too much, and the group loses a bit of its "Pop". Looking at the picture, I may simply suggest a Black-(whatever other color you see fit) backdrop, or increasing the canvas size and adding a Bold border to create an effect.
I can't truly critique much else, because your individual style is so far away from realism (or the franchises' own artstyle) that any 'irregularity' can be chalked up to being done on purpose.
Once again this is a fabulous piece of art, and I hope your work makes it onto the collection.