This one, but I think he was already out before pitching any story to the producers:
"Well, Brainiac. There was a little bit of Brainiac that was going to be in it, but no. Tom and I had some really great thoughts. Because he was also a good director. And what we were going to do was, we would write the next one [II] and I would direct that, and we’d do the third one and Tom would direct that. And so on, for as long as it lasted. But the producers [Alexander and Ilya Salkind] didn’t see our relationship to the films as we did, so I was not brought back.
Well, one of the villains, yes. I mean, I felt there was a different way of approaching it, but the intellect of Brainiac was very exciting."
https://heroichollywood.com/superman...rainiac-films/
Yeah, Zod/Braniac/Lex are the ones that keep being planned as main villains for every new adaptations but Brainy is the only one so far that didn't made into the big screen because everything he is written in gets cancelled. Dude is cursed lol.Makes sense, I mean he was the second biggest Superman villain for ages, if anything it’s a shocker it’s taken until (possibly, if the rumors are legit) Legacy for him to be used on the big screen.