I always tend to look at the pictures quickly... so I get a 1st glance opinion. My initial reaction was "COOL Stone Armor!!! And those eyes... so EVIL! PERFECT!" Then I read the comments and realized (after looking a 2nd time) that there are metal parts. I do not know if it is the photo (which BTW is VERY good!) or it is the technique.
If it is the ladder, I would suggest a diluted (with water) wash over with that Silver Mithryl Metal to separate the metal from the stone armor, and then a thin thin highlight on the razor edge. You want the observer's attention on the razor blades (sharp edges are evil!)
There is a nice 'classic' tutorial on Space Marine lens highlight... if you are intrepid, you could do that. That alone would take the model to a new height on the evil scale.
The base is really nice (shows you have some nice talent!) regarding the skull. I would suggest repainting the brown border, as there is some green on it, and maybe putting some DRY static grass (the one that is golden brown). This would make the skull 'pop-out' to the observer... which deserves great attention. You want to freak people out... make a red (scab red... the dark one) dots on the skull eye sockets. This would make people take a double-look to the model.
Keep posting the pics... you have GREAT talent man! Thanks for sharing!