After being defeated at Mustafar by his former master, Obi-Wan Kenobi, Vader was left severely injured, burned, and filled with anger and hate. He was encased in frightening black armor and given mechanical lungs that emitted an ominous breathing sound with his every step. Vader quickly became a symbol of the Empire, serving as Palpatine’s fearsome enforcer. He hunted down fugitive Jedi who had escaped Order 66, backed by the fearsome Inquisitorius. Vader's fall to darkness was punctuated by the resurgence of Obi-Wan about 10 years into the Empire's reign. Forced out of hiding, the former master and his fallen apprentice were reunited on Mapuzo. This time, it was Kenobi who was badly injured in the fight, suffering severe burns after being dragged through a wall of flame. However, Kenobi regained his health and his spiritual strength; when they clashed sabers not long after, Obi-Wan emerged victorious, leaving Vader with a shattered helmet, and stoking his seething hatred.
Based on Geektopia's Darth Vader - Jedi Hunter deck available here.