Originally Posted by Darth_Terros
You obviously havnt seen the prequel trilogy which is pretty much how he came to power and rule the galaxy ?
And then in Rots he tell you his master was plageus so that explains how he became a sith and obviously through years of training he became powerful the same way jedi who train for years do.
He never directly says that Plageuis was his master. At least, not in the movie I watched. o_o It only says that in the Novellization, I think.