Mutants!

These two crew members are both converted from Warhammer Gnoblars. I've seen the chainsword conversion before, though I don't remember who had done it.

The big shield on the right mutant is supposed to be some kind of portable shield generator to protect him from shooting while he shambles over to slay with his long-handled chainsword.

The guy on the left is supposed to be some kind of cybernetically-enhanced tracker with a cybernetic third-eye. He has an appropriately dainty laspistol and a pretty sketchy-looking cybernetic claw hand.