basically the simple concept of BC's Khan technically 'being' Khan, but not actually 'being' Khan. He's just assumed the name of Khan, and is actually the real Khan's top right-hand man.
Oh geez. Wow. I think that's giving them too much credit, personally; we thought for four years they were coming up with something great and new and they gave us a shoot-em-up rehashing of an old movie. not that I'm bitter. XB