One of Anakin Skywalker’s first acts upon succumbing to the dark side is to go on a full-tilt, child-killing murder spree, so it’s a little difficult to sympathize with the constant, consuming pain that he endures post-transformation. While Darth Vader’s armor is built from nearly impenetrable durasteel and provides a temperature-controlled climate, super strength, and intermittent pain relief, the suit is itchy, claustrophobic, unnecessarily heavy, and restrictive. The pauldrons alone weigh over 50 pounds, making any above-the-shoulder arm movements functionally impossible. What’s worse, Darth Sidious designed the armor to ensure that his apprentice continues to experience the pain of his wounds. The Sith Lord believes that fuels Vader’s obedience and, more importantly, his battle viability.
By leaving Anakin in constant agony with infrequent medical assuagement, Darth Sidious guarantees that his easily manipulated pupil remembers his weakness and who’s in charge. There is no excuse for Anakin’s actions as Darth Vader, but he’s trapped in a vicious cycle in which his only relief is to lash out against those his master deems unworthy to live. Pain is powerful, and no one knows that better than Anakin.