buddy-x-wing said:
the existence of a son means Vader knows the Emperor lied (from a certain point of view) about Anakin killing Padme, it also means the Emepror knows that Vader knows he lied to him about Padme's death, adds a bit more tension to an already interesting dynamic.

But does Vader know that the Emperor knows that Vader knows that the Emperor lied? And does the Emperor know that Vader knows that the Emperor knows that Vader knows that the Emperor lied? And does Vader know that..........my head hurts.