No, you still don't know WHO really was Darth Vader (DarthCoin). Go back and watch again all saga, and pay attention to all Darth's dialogues.

Darth Vader was never a sith. He was fooled by Palpatine to join him, because Palpatine promise to Anakin that he will get back Amidala. Anakin only wanted Amidala back, nothing else.

Darth wanted to bring BALANCE into the force, together with Luke, because they were the only ones that could do that. That's why he even asked Luke, "join me and we will bring peace and balance into the galaxy"...

Also on the Javin 4 they had a short discussion in the base, about the same thing. Luke in the last episode, on the island, he burned that jedi tree of knowledge exactly because he realized the mistake he did, not joining Vader years ago. He isolated himself exactly to NOT be that unbalanced into the force, he had too much power.

Please go back and study more about Darth Vader. Don't fall into the disney narrative that he's the bad guy, he is NOT.