I like the NMM on the axe, and the dusty build up round the feet. I think I’d like some pops of contrast worked in for the next one, maybe shoulder pads same as helmet, ribbons on the back pack could be red.
There’s a fine balance between getting the grimy effect and flattening out your contrast. A good tip I got a long time ago was to take a photo of your model with your phone, then make it black and white and see if it still works for you.