Is Brainiac the most convoluted Superman villain? This video goes into how convoluted the character is:

https://www.youtube.com/watch?v=oyBl8Usm_gM

There are different takes on Lex Luthor and he is fairly easy to follow, for the most part.

This video only covers Pre Crisis Brainiac and early Post Brainiac, not the more recent stuff, but it is this still a mess almost from the start. It may be why Brainiac often works better in adaptions in other media, where the back story can be more streamlined. If you think Brainiac is convoluted, how would you make him less convoluted?