From birth, Darth Vader's life had been about fighting. He fought against the chains of his slavery, against life itself on the desert planet of Tatooine. He fought in the battle to save Naboo, and played the critical role that allowed for victory to come. As a teen, he had helped to resolve various conflicts with his master; most of the time, they would end in "aggressive" negotiation. He had fought in the Clone Wars, becoming a respected general and a man revered as the Fearless Hero. He had ended his apprenticeship and taken on a student of his own, fighting by her side through countless battles. He had slaughtered the Jedi Order entirely by himself, hunting down and killing them one by one until the only ones left were Obi-Wan Kenobi and Yoda. Even then, he had avenged his arm and legs by slaying Obi-Wan inside of the first Death Star. The only Jedi he had not crossed blades with, including his son Luke, was Master Yoda; it was one of his greatest regrets that he never managed to have the chance to battle against the short and ancient alien. Perhaps Yoda could have ended his suffering.
War was his gambit, the overarching theme in his life, and he would be lying to say that he wasn't good at it. Even with his body encased within black, and his mind corrupted by hate-fueled rage, there are none who could fail to acknowledge his unparalleled skill with the blood-red lightsaber which he wielded. It was a behemoth of a blade, far longer than most of the rest of its brethren. It stood only a few paltry centimeters shorter than him, including its hilt, and could hardly be called a close-range weapon by any who saw it in action.
His rage was legendary, and he was feared for it. Often, he exploded with seemingly little provocation; he was quite famous for the number of staff changes and promotions he granted, though it was due to how many officers he'd killed. It was his way of fighting back, in a sense, almost in the same way that he had in his boyhood: passive destruction, eliminating things that wouldn't be noticed by the one who enslaved and owned him. It was petty, but it was all that he could ever do.
He was a fantastic pilot, regarded as the galaxy's best, and it had been in a podrace that he'd won his long-sought freedom. From there he had piloted all kinds of ships, be they fighters or cruisers, and each one had been like an old friend. He would occasionally wonder about what had happened to his first true craft; did it rest in Jabba the Hutt's palace walls, enshrined with many other victor-crafts that had won in earlier or later years? It had been his first real battle, and he had won.
His cunning and gift for aggressive strategy never left him, only growing stronger as time went by. After years of fighting against the Rebel Alliance, the ragtag freedom fighters learned to flee when he arrived on the field. He idolized them and revered them, in secret, because they did what he could not: they dared to challenge the Emperor. More than that, they rose against the man who they feared even more than Palpatine: Darth Vader himself.
The violence in his eyes was hidden behind the black helm which keeps him alive, but that never stopped anyone from realizing that they were going to die. In their final moments, they would hear a wordless march of terror and doom, slowed to agonizing levels; their muscles would freeze, and it would seem to take an eternity for Vader's lightsaber to decapitate them. It was all a mind trick, of course, but that did not make it any less terrifying for those who were unable to comprehend the power of the Force that the Dark Lord was so in tune with. It only increased his capacity for violence and bloodshed, and he had only ever used it for those two purposes alone. The Dark Side of the Force was truly fearsome, and none were able to prove it as well as the man who was the Chosen One.
His ferocity was ever unbridled, and ill-contained. He had struck down one soldier after another, one leader before the next. Even against his own son, he had been far from lenient; he had taken the boy's right hand from him, in a wound for Luke to be more similar to his father, and had never failed in his cruel barbs at the young Jedi's emotions...not that Luke would have been considered a true Jedi Knight in the days of the Old Republic. The child had been trained by two masters, and certainly had a high-enough midi-chlorian count to wield the Force with a level that matched the Emperor in capability, but his swordsmanship was poor. The boy fought with his senses, not his feelings, and it had almost been the death of him.
Almost.
Darth Vader had risen up and unleashed his unshakable fury for the last time in his life, having finally found the courage to break through his inner darkness. His wrath was powerful, almighty, and the ultimate example of why he was the Chosen One. Even with his body being more machine than man, he could manipulate the Force in such a way that Palpatine's lightning could barely fry his circuits. In theory, it should have been more than enough to allow the Sith Lord to survive...though the same could not be said of the Emperor.
That had been in theory, however. In practice, Palpatine had managed to destroy the one unit that Vader needed intact in order to keep himself alive. The irony was not lost upon him that, as he had spent his childhood of slavery fixing machines, the very thing which would kill him was to be a mechanical malfunction.
That was his final battle, he had known. There would be no more war in his life, or in his heart or mind. His mask removed, he saw his son with his own eyes; the price for peace was unbearably high, he had thought, that he would need to once again leave his family behind as he went down a path which they could not follow. But, for all that it would cost him, he could not keep himself alive for much longer other to convince his son that he must leave the Death Star before it is destroyed.
Darth Vader's death was peaceful.