What would be great would be to have him smashing the exterminator robots that are attacking Lucca in the animated opening. Given, for pretty much any scene that you do, you're going to have to make more characters. All of the tiny bits of scrap and sparks from the robots being smashed may take awhile, especially making each one look like it's been crunched in different spots.
An alternative would be to have him when he fires his fist at the Black Tyrano. You'd have less extras to worry about when it comes to making individual characters and background. Besides, imagine how satisfying it would be to get that dinosaur done.
Another one you could do, one that would probably be the easiest, would be to do the duel between him and Atropos. Just a bit of recoloring and a turquoise bow on the back of her head. You could also do the Mother Brain. You wouldn't have to try and texture everything, just leave it glossy and give it some coloration, maybe have the computers in the background.
Regardless of what scene you have him in, I think he'd look great. He's pretty much exactly as I'd imagined him to be, and unless you were to zoom in to ridiculous degrees to get each little grain on the cloth or something, you couldn't have done better. Great job!