Force lightning channels the force through the body, actually, so it would have blown up vader's support system. And vadfer wanted to destroy palpatine, actually, in ESB he tells luke to join him and overthrow the emperor. if you look here at the "Bahind the Scenes" section http://starwars.wikicities.com/wiki/Darth_Vader you'll see what I meant, about him being twice as powerful as the emperor...