In the comics, for example, it was shown how the Jedi hermit Kirak Infilla almost defeated Vader when the Sith Lord came after him to take his lightsaber, according to Sith tradition.
By the end of their duel, Cere left Vader burnt, limping, and wheezing, proving Vader wasn't all-powerful. Ultimately, she came closer to killing Vader than almost any Jedi in Star Wars canon, though her overzealous attack ended up being her downfall.
While Vader had his weaknesses, including vulnerability to electricity, characters like Emperor Palpatine, Mace Windu, Yoda, and Obi-Wan Kenobi all had the potential to defeat him in battle.
Despite his apparent power and strength advantage, Cere holds her own against Vader and he isn't so hard to beat. She manages to weaken him severely and gets a chance at a final, fatal blow but is tragically cut down by a swift move from Vader. He only barely survives the fight, staggering away in pain.
Infil'a put up a fierce fight against Vader, almost killing him by throwing the already damaged Sith Lord off of a cliff. Despite severe damage to his suit, Vader survived the fall, and repaired himself with parts from Infil'a's droid, Arex.
What If Anakin Skywalker SPOKE TO Darth Vader In Revenge Of The Sith
Would Kylo Ren beat Darth Vader?
Kylo and Rey (Daisy Ridley) also blasted the Imperial Crusier open trying to Force pull the Lightsaber away from each other, so clearly, Kylo Ren is an extremely strong Force-wielder. Nonetheless, it can be said that Darth Vader is the more powerful master of the Force for one key reason: his temperament.
During the battle, Anakin, who had been known as the Sith Lord Darth Vader, was redeemed by Luke and brought balance to the Force. However, the redemption cost Anakin his life, having been mortally wounded by the Emperor, Darth Sidious, while killing his former Master.
While their duel on Malachor was interrupted before a victor could emerge, the damage sustained by the Sith Lord was evidence enough that Ahsoka could beat Darth Vader.
Surprisingly, not every Jedi was marked for immediate execution. Certain Jedi, such as Jedi Knight Iskat Akaris, were spared from the immediate onslaught of Order 66.
Yep. Darth Maul didn't really say or show straight up that he "feared" Darth Vader, but he openly stated his belief that he could not defeat Darth Vader without the help of the Jedi, therefore on his own.
In the Star Wars Universe, it's hard to deny Darth Vader's greatest enemy was the Jedi Order. Sure, he had enemies such as Qi'ra, the Crimson Dawn and Doctor Aphra. But few came close to truly defeating him, other than Obi-Wan Kenobi and in time, his son, Luke Skywalker.
This is a rare problem for him to come up against, due to only other Sith commonly utilizing such a capability. However, in Return of the Jedi, the force lightning used by Emperor Palpatine is shown to be immediately and vitally debilitating to Darth Vader.
So, if not Palpatine, who could Vader possibly fear? Well, the answer is deceptively simply, yet incredibly shocking all at the same time: Luke Skywalker.
Vader utterly despised Palpatine, and did for a very long time. After Padme died and Palpatine blamed Anakin for her death, this ignited a spark of hatred for his master that would stay with him forever, Anakin blamed Palpatine for Padme's death, and probably his injuries too.
The only Sith Lord who actually killed Vader, Darth Sidious kept his apprentice in line for over two decades. His true advantage was Force lightning, a power which would wreak havoc on the suit keeping him alive.
Yoda's presence on Dagobah was likely hidden due to his mastery of Force Stealth and the planet's connection to the Force. Yoda, with his enhanced Force abilities and potential home-field advantage, would have had the upper hand against Darth Vader if they engaged in a lightsaber duel.
Admittedly, Rey skills couldn't possibly be as developed as Anakin's or Luke's. Nevertheless, considering how fast of a learner she is, and how unique the powers she possesses are, it's not a stretch to say that Rey could be a more powerful Jedi than Anakin and Luke Skywalker.
The realistic answer seems to be, yes, Anakin in his prime could have defeated Luke Skywalker (in the current canon) if they battled one-on-one. The main reason behind this is Luke's lack of formal Jedi training, at least when it comes to combat.
A year later, in 4 ABY, with his health rapidly declining, Yoda died of old age when Skywalker returned to see him. He became one with the Force, shortly before Luke redeemed his father Anakin, who fulfilled his destiny as the Chosen One by killing Sidious.
Their battle was interrupted when Leia used the last of her strength to reach her son in the Force. While Kylo was distracted, Rey ran him through with his own lightsaber, leaving him mortally wounded.
Darth Vader's final words were “if you will not turn to the dark side, then perhaps she will”. Anakin Skywalker's final words were: “You were right. You were right about me. Tell your sister…you were right”.
Although her midi-chlorian count is never mentioned, it is clear that Rey's potential is vast. While Vader has peaked in his Force-prowess, Rey is only getting started. Even if Vader is currently more skilled, Rey definitely has more raw power.
Given the years between these comics' publications, it's hard to tell if Gillen built this argument intentionally or not. Regardless, the core concept is still true. Thanos wields more power and authority than Darth Vader, existing as a stronger and more capable villain overall.
Kylo lost to Rey in TFA because he was heavily wounded and was holding back against her due to Snoke's request that he bring her back to him alive. He is also stated by Palpatine in the Secrets of the Sith book to be “equally as powerful as a real Sith despite not being one”.
