R6D9 said:

Lets think about some real issues why did Vader want to stay on the dark side after Padmai died? and why did he not just kill Darth sidius after she died i mean his only reason to join was her so what was his reason for stickin with it

Well if you take ROTS as a reference, one gets stupid when turns to the dark side. It is not like Anakin screwed up and is trying to save his skin when he knew all too well he was tricked (hell even Sidious himself admitted to him that he is the Sith Lord they are looking for). Instead he becomes stupid and screams "From my point of view, the Jedi are evil".