Re: Who should be the villain in the sequel for Man of Steel?
I think it's hard to say until we see this film.
I mean, if MOS is exploring A LOT of the sci-fi aspects like some rumours are leading us to believe (alien ships), then Brainiac is a logic second villain IMO (and I'd hope that Lex would be in the mix too, because he should be in all Superman stories).
But if their going for a more Nolanesque type story I'd expect something more along the lines of Intergang/Lex trying to create technology that could fight against Superman (and other aliens, since their experience with Zod and Faora). I.e. Metallo/Parasite.
Just accept that this is the direction they have taken.
Then, you can either decide this version isn't for you and stop watching. OR you can decide to enjoy it for what it is - an elseworlds tale.
'In Elseworlds, super-heroes are taken from their usual settings and put into strange times and places - some that have existed, and others that can't, couldn't or shouldn't exist. The result is stories that make characters who are as familiar as yesterday seem as fresh as tomorrow.'