Though I doubt this is what Gunn had in mind when he said Cavill could return as a different character, I think Cavill would make for an exciting Brainiac.
I like the idea of Brainiac being the ultimate alpha, like Lex taken to its scary conclusion, capitalistic success embodied in a being, the synthetic body kind of looking like creepy plastic surgery. Not only does Cavill kinda have that robotic soulless thing down pat (like his MI villain, and his evil Supes), Brainiac with the face of a former Supes would further sell the idea that Vril Dox was once a hero, a great contributor to Colu as its most brilliant scientist, before he was overtaken by ambition, losing his soul, immortalizing himself in a perfect synthetic Giga Cavill body, and setting his sights to space (X) to continue growing his assets.
