Grim Master is a cool name. Sounds like a Darth Vader type of dude. That's Dinopope, yes?
Also, more Microns are never a bad thing. Not interested in the Prime himself though, so will be missing out on these little dudes. Since it looks like he has a sword/halberd sort of thing, I'd say Ratchet's maybe Arcee's, likely his own, maybe Soundwave's, and Bee's?
assembling a Neo-G1/TF:TM cast. Please PM if you have (or know of) the following at a reasonable price: Classics or Henkei Astrotrain, Ramjet, Sunstreaker, Sideswipe, Blurr, or 3rd Party Motobot Arcee, iGear Ratchet and Ironhide.
Also looking for Universe Repugnus and Overbite, Frostbite and Longhorn