For Man of Steel 2, I want to see Lex and Brainiac. However, I want a lot of what Brainiac was in the proposed Superman Returns sequel to implemented, if it's not already going to be used for Zod. But ultimately, he is out to destroy Earth. As for Lex, they need to get him right. I want him to be the Lex we see in All-Star Superman. He needs to he driven by jealousy, he spent his entire life in devotion to becoming the best of everything, to becoming the philosophical übermensch, and along comes this alien who was born with all the talents he has to work for, and for that he is hailed as the first son of Metropolis, while Lex is forgotten. What would be a bonus would be if they can put in that scene from Birthright where Lex manages to make contact with Krypton (with Brainiac tech) and Superman can tell his parents he made it safely to Earth, before they die.