Originally posted by proffitt
(Mechanical) Vader cannot block/absorb force lightening due to his artificial limbs. The Ep. III Visual Directory states that because of his mechanical arms/legs, Anakin/Vader can never learn to conjure nor be invulnerable to Sith lightening. The reason he "Must obey" his master (ROTJ) is because, for one, he knows that Palpatine would fry him. IF he had his light saber fried like Yoda's was, then Vader would be at Palps mercy. Just a thought.
Doesn't he have one non-mechanical arm left. Couldn't he absorb/reflect/cast some force lightning with that. Everyone else either absorbed, deflected, or cast it with only one hand.