I like this one (in OP) more. The deviantart one was widely criticized from a long time ago since it's twice as big as the retail Sathanas, and because it has weird muscle/tooth structures going on.
The deviantart one also looks better because it's textured.
Suggestions for front claws:
Need engine thrusters. This is pretty much a must.
Consider working in some sort of greeble into the claw area. Or, do something to up the detail/interest of the huge red spikes.
Consider a way to make the actual beam turrets (the tips) look separate yet linked to the rest of the arm. When you kill a turret, it should visually make sense why the part that exploded did.
Consider a way to subtly suggest that the arms can pivot, as per the Supernova cutscene. Never mind, saw the joints in the arms.