DARTH VADER

Before Anakin Skywalker became Darth Vader, he was a kind person who cared about all of his friends. He wouldn’t give up on them no matter what the cost. Despite his compassionate and sympathetic demeanor, however, he was pretty heartless and aggressive towards people he considered his enemies, most likely due to how he was treated by his enemies. Even before he joined the dark side, his actions proved that he may have been unfit to be a Jedi, so much so that Obi-Wan was cautious around him even after they formed a strong Master-Padawan bond.

The deaths of Qui-Gon Jinn, his wife Padmé, and his mother Shmi, left a deep impact on him; feeling alone and failed, he ultimately embraced the dark side of the Force and his personality changed completely. He was utterly ruthless and intimidating now, driven by rage, though after his defeat and mutilation on Mustafar at the hands of Obi-Wan Kenobi, he was no longer as arrogant and overconfident as he previously was. Although he regained confidence in himself, it was never to the point of being outwardly cocky or conceited. This calm approach made him much more efficient than most of the Sith Order as his pragmatic nature made him less likely to underestimate his foes.

Unlike most members of the Sith Order, Vader was capable of acknowledging and learning from his mistakes, due to the events on Mustafar as he was emotionally traumatized by the experience. He is, however, a bit boastful when dealing with opponents he considers inferior.

Vader remained an impatient man, but generally presented himself as calm and level-headed, as he rarely lost his patience and typically had good control over his emotions, something he was not able to do in his early twenties. Due to his unstable mentality, Vader would often rest and meditate in either his meditation chamber or elsewhere where he would tap into the Force and focus on concentrating his mind. However, his level-headed nature had limits as shown below.

He had an extremely low tolerance for failure and he did not get along with most high-ranking officers in the Imperial military at all. He had little to no tolerance for incompetence or for those who disrespected him, nearly choking Admiral Conan Antonio Motti to death when he disrespected Vader and challenged his powers of the Force. By the time of the Battle of Hoth, Vader’s intolerance for failure had reached such extremes that he became known to kill his own men for making even the slightest mistakes. Many higher-ranking officers disliked the Sith Lord and his "sorcerer's ways" for no apparent reason.

Despite his bad relationship with most high-ranking officers in the Imperial military, Vader got along with the Stormtroopers very well because of his front-line leadership. He is also more compassionate towards them than most of his superiors as long as they obeyed him. As the Supreme Commander of the Imperial Armed Forces, Vader was renowned for his leadership skills and admired by stormtroopers, middle/low-ranking officers, and politicians alike.

Because of his former status as a slave, Vader had distress when the concept of slavery was brought up. Despite what his actions wrought upon both himself and the galaxy, Vader obviously believed he was doing what was good for the galaxy. Deep down, however, he felt enormous guilt and remorse for his actions, whether he wanted to admit it or not, so much so that he developed a deep self-loathing, and even nearly committed suicide at one point.

Upon his fateful reunion with his former apprentice and friend Ahsoka Tano, Vader expressed no desire to rekindle the bond he once shared with her and even told her that he killed Anakin Skywalker when he was in fact Anakin himself (though he may have been speaking ironically). Though he did offer to spare her if she told him where the other surviving Jedi were hiding, he cruelly resolved to kill her when she declined and even when she found out that he was indeed her former mentor and offered him compassion.

Vader was cold-blooded, brutal, and relentless towards his enemies, as he was ready to tease, torture, and even kill them in cold blood. He was seemingly unfailingly loyal to his master Darth Sidious; the latter was the closest thing Vader had to a friend. However, in truth, he hated his master for deceiving him and ruining his life, as he secretly planned to overthrow him with his own apprentice someday.

The only reason Vader continued to serve Sidious after losing his wife was that the Emperor was all he had left; he was the only one that would accept him. All in all, Vader was only loyal to people he still cared about for real, like his son Luke, as he did everything possible to protect him from the Emperor. In addition, Vader maintained loyalty to Qui-Gon Jinn despite the latter's death, as he viewed him as a father-figure.