The only safe place to stand when a Warboss is concerned, behind him!
As you can see the powerpack for his legs was ripped straight off a multilaser powerpack, the boss was getting impatient so they didn't have time to respray it either.
Also this shows the rusted detritus on the ground behind him, I love painting rust now, base of the red foundation paint, dark flesh over that, dry brush dark orange in dabs and on the edges, then with bright orange very lightly on the edges. Add a light stippling of metal here and there if you want it to look less rusted.