I would not want his robot mode to be humanoid at all. I would like it to be a bizarre tangle of claws, limbs, spikes, and maybe a few tentacles. His head would have to look way crazier and weirder than movie-verse Devastator's. I don't actually expect him to be in any movies; I'm just throwing in my 2 cents. And if Primus showed up too, to lay the smack down on Unicron, he wouldn't look humanoid either, but would look tamer and neater.