While many Star Wars fans considered Luke's decision to go into exile to be opposed to everything that defined him as a hero, this is somewhat the point of the decision, as the collapse of his family and his new Jedi Order broke Luke in a way that he only recovered from at the end of his life.
After his failure to train a new generation of Jedi, Luke Skywalker went into self-exile on the planet Ahch-To, shutting himself off from the Force and intending to spend his last days marooned and alone.
Luke went into hiding after his nephew and apprentice, Ben Solo, turned to the dark side and became Kylo Ren, a warlord of the tyrannical First Order and its leader, Snoke. When Ren killed all of his fellow apprentices and ushered in the fall of the New Republic, Luke felt responsible, and disappeared.
Luke didn't just "cut himself off" from the Force; he felt unworthy of it. He felt the Force no longer needed him or his hokey religion and ancient weapon. It did, of course, just not the way he thought.
Luke's decision to allow himself to pass into the Force indicates that he believes he has reached the end of his journey, signifying a deep-seated inner peace that any Jedi reveres.
Luke dies in The Last Olympian when he is given Annabeth's knife by Percy. He sacrifices himself to defeat Kronos by stabbing himself under his left arm where his mortality was still kept intact after his bath in the River Styx (known as his Achilles heel).
Enraged that he was given a quest with no glory (because Hercules did it once) and then failing, and his belief that the gods let Thalia die, Luke began to plot against the gods. Luke dreamed of Kronos, who convinced him to serve him and help him start a war with the gods.
The Emperor's foot attempts to turn Luke's hand to the dark side of the Force. However, Luke's hand once again refuses to be turned and the Emperor's foot attacks him with the Force, causing Luke's hand to lose its thumb.
Rey learns from Luke why Ben Solo turned to the dark side: Luke had seen a vision of the destruction Ben would cause and was briefly tempted to kill him in his sleep; when Ben awoke to see Luke with his lightsaber drawn, he turned on his uncle and apparently destroyed the Jedi Temple.
In his conversation with Luke, Yoda implies that one must become a Jedi Knight in order to be a full Jedi, and that's why he asserts that Luke is the only Jedi left by the time he becomes a Knight.
It was believed that Grogu would eventually become a victim of Kylo Ren's destruction of Luke's Jedi Order. However, The Book of Boba Fett revealed that Grogu chose to follow the Way of the Mandalorian rather than become a Jedi, sparing him from Kylo Ren's wrath.
The son of Han Solo and Leia Organa, Ben Solo was seduced by the dark side of the Force and renamed himself Kylo Ren: leader of the Knights of Ren, champion of the First Order, and apprentice to Supreme Leader Snoke. Driven to destroy the past, Kylo killed his father and his master, supplanting Snoke as Supreme Leader.
Not only did Ben care little for the Jedi, he also viewed Luke as the person keeping him away from his parents. And the strict rules of the Order only made matters worse, as Ben felt they limited his potential, and forced him to forgo attachments.
Kylo develops a close relationship with Rey and starts feeling genuine affection towards her, so when Snoke reveals that he had manipulated their bond and tortures her in front of Ren, he looks furious at his master. Thus, when Snoke orders Ren to kill Rey, he chooses to save her and kill his master instead.
The aged Jedi Master had given up on the Force, blaming himself for Ben Solo's fall to the dark side. Luke eventually relented, but he was clearly wary of repeating his past mistakes. In one key scene in Star Wars: The Last Jedi, Luke watched with fear as Rey dove straight into the dark side of the Force.
This caused him to attempt to assassinate him in his sleep. Needless to say, Kylo Ren is almost definitely a significant threat. However, we cannot definitively say that he is more powerful than Luke. Kylo's powers are vast but they are still highly unbalanced and difficult to control.
Following Palpatine's final defeat and her own resurrection, Rey adopts the name Rey Skywalker to honor her mentors and their family legacy and renounce her lineage.
Kylo Ren dies on Kef Bir (the ocean moon of Endor) shortly after Rey deals a mortal wound during a lightsaber duel on the wreckage of the second Death Star. Though Rey Force-heals him, saving his life physically, this blow, coupled with the memory of his mother and father, destroys the man known as “Kylo Ren” forever.
Luke confronted the Dark Spirit in the form of Darth Vader within and defeated it in a lightsaber duel, dipping into the passion of the dark side in the process. It was there that he realized what would happen if he turned to the dark side of the Force. Behind the mask of Darth Vader, he saw his own face.
History. Like many Jedi did for hundreds of years, Yoda built his lightsaber under the aegis of Professor Huyang, an architect droid who had been with the Jedi Order since its nascent days. As a first step, Yoda acquired a kyber crystal from the icy caverns of Ilum, a mission that proved to be very eventful.
Luke's emotional nature leads to his downfall, shown when he loses his hand in a duel with Vader. Luke's reliance on violence causes problems throughout the original trilogy and hinders his growth as a teacher.
The Last Jedi forgets that the Sith were destroyed long before the birth of Ben Solo (before their survival is retroactively confirmed in Star Wars: The Rise of Skywalker), yet he lists them as one of several factions that he and Rey must let go of, as though Snoke (an unaffiliated dark side user) and Kylo Ren himself ...
Anakin Skywalker was supposedly the "Chosen One," a destiny that Luke later inherited. Vader spread terror through the galaxy. 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.
