He became apprentice to Darth Sidious to bring peace to "his new Empire," consumed by a lust for power. Luke Skywalker's arc actually repeats many of the same beats as Anakin's, as Luke drew ever closer to the dark side himself.
After being defeated in battle, Darth Vader offered Luke a choice; he could join him, finish his training using the Dark Side of the Force as his apprentice. Luke accepted and finished his training as a Sith Lord.
Why did Palpatine want Luke to join the dark side?
Luke Skywalker's dark side potential revealed in Star Wars #43, showcasing raw strength and expertise. Luke harnesses the pain of losing his hand to unleash dark side energy, proving he could be a powerful Sith. Palpatine's interest in turning Luke to dark side is justified by Luke's display of immense Force power.
To understand his father's decisions -- and to better understand the nature of the Force -- Luke allows himself to go to the Dark Side, not out of hate or fear, but in the pursuit of wisdom. Meanwhile, the New Republic forces are attacked by a new type of Imperial superweapon known as World Devastators.
Why Luke Skywalker Wanted Jedi to Use the Dark Side | And Why It Saved Them
Why is Darth Vader obsessed with Luke?
Ricocheted away from the Death Star and spun out of control, Vader was unable to stop Luke. The space station was destroyed, but Vader survived, and he flew into the far reaches of space. After the destruction of the Death Star, Darth Vader became obsessed with finding Luke Skywalker.
Vader's only goal in the fight was to make Luke lose control of his emotions and bring him closer to the dark side -- and that's exactly what happened.
By bringing weapons into the Dagobah Cave, Luke already failed the test. Even Yoda explicitly said he will not need weapons. But like any young acolyte, Luke doesn't listen and takes his belt of weapons. He's focusing on the immediate threat (Darth Vader), and doesn't understand that being a Jedi is a journey.
The dark side tempted Luke Skywalker to kill his father, Darth Vader. Luke Skywalker was tempted by the dark side when he attacked his father in fear of losing his sister just like Anakin Skywalker pledged loyalty to Darth Sidious in fear of losing his love.
Lucas had developed the characters Luke and Leia as twins, and the suns reflected this “mythological significance” according to “The Making of Star Wars” by former Lucasfilm executive editor J.W. Rinzler. The visual motif has followed the Star Wars saga ever since.
Why didn't the Jedi sense the dark side in Palpatine?
Palpatine used his powers to hide his true nature from the Jedi, utilizing Force Concealment to completely hide his presence in the Force while clouding the Force for the Jedi. The Clone Wars also kept the Jedi busy and weakened, preventing them from realizing his true identity.
So while Luke may have bested him in terms of athletics, Palpatine's Force-powers could very likely give him the victory. So while fans may never know for sure, it would've likely been a very close battle, with neither side being a clear victor.
Kylo Ren wanted to be the next Darth Vader, fundamentally misunderstanding his grandfather. Another key reason why Kylo would never be the next Vader was that Kylo was a Knight of Ren, not a Sith. While both religions used the dark side, and red-bladed lightsabers, the two had different philosophies.
Summary. Kylo Ren's character arc in the Star Wars sequel trilogy closely mirrors Darth Vader's, but he was never a Sith like his grandfather. The only Sith act that Kylo Ren committed was when he betrayed Supreme Leader Snoke, following the Sith Rule of Two.
It is revealed that Ren is the son of Han and Leia, originally named Ben, and was once one of Luke's Jedi pupils. He was corrupted to the dark side of the Force by the First Order's Supreme Leader Snoke (Andy Serkis), and helped destroy Luke's new Jedi Academy.
Those who wielded the dark side found many abilities of the Force easier to use, with some Force powers. Light-side Jedi could use dark-side abilities, (even as some darksiders used light side powers) but most preferred not to since dark-side abilities had aggressive, destructive, or perversely manipulative tendencies.
Anakin's fall to the dark side came as a major surprise to the Jedi considering his status as the prophesied Chosen One. However, Anakin's redemption and fulfillment of the Chosen One prophecy where he brought balance to the Force came decades later in Return of the Jedi.
A Jedi needs to be a selfless servant, not an aggressive warrior. Yoda's teachings were focused on balance, both literally and figuratively. He wanted Luke to gain an understanding of the Force so that he would not be consumed with the prospects of combat.
According to Filoni, Yoda's words were not meant to be taken literally as other Jedi are certainly alive. Instead, Yoda meant that Luke is the last person trained by Jedi like Yoda and Obi-Wan, with the sole objective of defeating the Sith.
Although there were very few Jedi left in the galaxy, Yoda initially refuses to train Luke as a Jedi, partly due to his age and mainly because he believed Luke to be too much like his father, Anakin Skywalker, in personality (reckless, impulsive, short-tempered, and hot-headed).
Since Anakin's defeat on Mustafar, he needed frequent visits to his bacta tank to survive, and even the Vader suit itself was crude enough for Palpatine to control him. So with an aged body, a mind out of balance and the surprise of Luke's attack, Vader was caught at his weakest point.
The implication is clear - that this is Luke Skywalker at his peak, equal in power to Darth Vader but a champion of the light nonetheless - but Star Wars is yet to confirm that this was indeed the case.
