Six famous Sith Lords bearing the Darth title, from left to right: Darth Andeddu, Darth Revan, Darth Malak, Darth Malgus, Darth Ruin, Darth Bane. Many Sith Lords chose to add "Darth" to their name, so much so that the word is considered synonymous with the dark side of the Force in some circles.
Although it's not fully clear where the Darth moniker originated, Darth Andeddu is thought to be the first character to use the title in-universe. Having originated in Legends, Andeddu was mentioned in the new canon in the comic Star Wars Adventures: Return to Vader's Castle 2, which referenced "Andeddu's flames".
So technically, from the moment Vader was subsumed by Anakin, he ceased being a Sith Lord. So by the time he had Sidious up in his arms, he was the Jedi Knight (“We do not grant you the rank of master …”) killing the final Sith Lord, who was Sheev Palpatine / Darth Sidious.
After the Sith were decimated by the Jedi Knights of a thousand years ago, Bane enacted the Sith rule of two: there would be only two active Sith at one time -- a Dark Lord to embody the power, and an apprentice to crave it.
Every Dark Lord of the Sith - Star Wars Canon and Legends
How many Sith can exist?
The decree commanded that only two Sith Lords must exist at any given time: a master to represent the power of the dark side of the Force, and an apprentice to crave it and train under the master and to one day fulfill their role.
By the end of The Rise of Skywalker, Emperor Palpatine (aka Darth Sidious) is believed to be the last of the Sith Lords. But was he really the last to ever live, or were there others in hiding? According to the current canon, he is indeed the last Sith, but that doesn't appear to be the case in Legends.
History. A dark side warrior with a mysterious past, Kylo Ren was neither Jedi nor Sith, but a product of both sides' teachings. Once an apprentice of Luke Skywalker's, he killed his fellow students and drove Skywalker into exile, becoming a First Order warlord and servant of Supreme Leader Snoke.
Summary. Jar Jar Binks's clumsiness may not be genuine, but rather an act to disguise his true nature as a Sith Lord infiltrating the Republic. Palpatine carefully orchestrated events to manipulate the galaxy, and Jar Jar's involvement suggests he may have been the eyes and ears on Naboo.
Legend had it that Yoda—a Jedi who became Grand Master—was trained by N'Kata Del Gormo. A Force-sensitive Hysalrian, N'Kata Del Gormo was trained in the ways of the Force and achieved the rank of Master within the Jedi Order.
Even though Kylo Ren uses a red lightsaber, harnesses the dark side of the Force, and wears a cape, he is not a Sith. Because of that, he can never hold the title of Darth. Instead, he was just a chaotic mess of the dark side (until he eventually found his way back to the light).
Yoda's 900 years of Jedi experience and knowledge would be weaponized on a scale never conceived. Sith Yoda's destructive power would be so strong it could wreck the entire galaxy. Once Dooku saw the vision, he couldn't deny the threat a Darth Yoda would pose. Of course, Yoda didn't turn to the Dark Side.
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.
The obvious answer is Darth Vectivus, a Sith Lord who lived in his house and didn't try to conquer the galaxy or destroy the Jedi. And while he wasn't evil, he wasn't good, either. However, there is one good Sith. That would most likely be Darth Vectivus.
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.
As Darth Vader, he was one of the strongest beings in the entire galaxy. But even then, he was never able to surpass his master, Darth Sidious. A Sith Apprentice can only become the master when they murder the one who trained them.
Anakin Skywalker's birth mystery is solved - his mother, Shmi Skywalker, reveals that there was no father and she can't explain what happened. Qui-Gon Jinn believed that the Force itself created Anakin in Shmi's womb, making him the Chosen One who would bring balance to the Force.
Darth Gonk (Later Darth Wrife) was a force sensitive droid. He reigned during the first years of the Galactic Empire to the years of the Fel empire. He had a vast knowledge of the force that even rivaled the most powerful sith, such as Darth Sion and Darth Maul.
Rey Skywalker, known only as Rey throughout the First Order-Resistance War, was a human female Jedi Master who fought on the side of the Resistance during the war. A former scavenger from the planet Jakku, her life was changed by the tumultuous events of the last days of the New Republic Era.
Count Dooku was a menacing Sith Lord and central figure in the Clone Wars. Once a Jedi -- trained by Yoda -- he became disillusioned with the Jedi Order and thirsted for greater power.
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.
Emperor Vitiate was a Sith Lord who successfully gained near immortality by draining the life force of an entire planet, later attempting to drain all life in the galaxy, which would give him true immortality.
By 44 ABY, the true Sith species in the Empire were believed to have gone extinct due to the interbreeding process. Characteristics shown would be determined depending on how much Dark Jedi or Sith blood an individual possessed due to interbreeding.
