Hmm, as far as Lando goes, does he even consistently "add" to the series? That's not to say I don't love Lando. He certainly added a unique quality to ESB: an ally you're not sure you can trust who does do what he thinks is right for the people he is responsible for but doesn't necessarily overlap with what's right for the heroes. But does he really "add" anything to ROTJ? Again, I love Lando's section of the film, but, like a lot of the other returning characters, he's basically given a good-guy thing to do and does it, so I can't say he really added anything in that one, any more than I can say Han really added anything to ROTJ.