He's big, bad, and ON FIRE! He's the Fallen, one of the first 13 Transformers created by Primus. I owned the Titanium Fallen but absolutely hated how he fell apart every time I tried to pose him. So it was back to the drawing board, heh. The main body is the Classics 'Ultimate Battle Megatron' from the two-pack that came with Optimus prime, the head of the Titanium Fallen, and some FF Human Torch flames. The paint job is simple: basecoat black, line in with bright orange, then make a smaller line in those with yellow. I made a removable right hand (because Megatron didn't come with one) and the flames magnetically attach on his shoulders. Now we have a Fallen that can stand tall!
The Fallen even has his shoulder-mounted rocket launcher too. Can't remember what I made it from but you could use any sort of scaled missile/rocket launcher for this.