1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
As the first Dark Lord of the Sith, Ajunta Pall founded the first Sith Empire and expanded it onto other worlds. The Sith took over the planet Ziost and created it as their capital and as Pall's new home. Pall eventually died after serving the Empire for many decades, but his Empire lived on.
Truly, the most powerful Sith Lord was Darth Sidious, better known in his public persona of Chancellor (later Emperor) Palpatine. Through cunning and manipulation, Sidious killed his master to claim the mantle of Dark Lord of the Sith.
As a Sith Marauder in the Great Sith War, Sion fought for Exar Kun's Sith Empire until the day he was struck down. Rather than die, though, Sion found that by calling on his pain, anger, and hatred, he could rise from certain death and achieve immortality, at the cost of all-consuming agony.
DARTH SION : THE IMMORTAL SITH LORD WHO MASTERED PAIN AND DEATH Star Wars Theory. DARK SIDE FRIDAY - Darth Sion is definitely one of the most powerful Sith Lords. Sion's deep pain and rage channeled the Dark Side allowing him to cheat death.
During the Battle of Endor in 4 ABY, Sidious was killed by a redeemed Anakin Skywalker, who turned back to the light side of the Force and threw Sidious down a reactor shaft to save his son Luke Skywalker.
Nihilus consumed planets on several occasions, caring only to appease his hunger, allowing the dark side to consume him more and more each time he indulged his ever-intensifying hunger. Alongside his hunger, his power also grew dramatically, until he eventually surpassed his Master.
Galen was secretly trained as a Sith Lord apprentice to Vader, but returned to the light side and the Jedi. Galen Marek is the only one who came close to destroying the Sith Lord, thanks to his vast knowledge of Vader's fighting tactics through the many hours they trained together.
According to Star Wars Legends content, the first Sith was a former Jedi Master, Ajunta Pall, who became a so-called Dark Jedi, or “Fallen” Jedi. As the name implies, these Force-sensitives chose to practice the Dark Side, and rejected the Light Side of the Force.
In the Star Wars Legends continuity, the founders of the Jedi Order were Jedi Masters Cala Brin, Garon Jard, Rajivari, and Ters Sendon.
Yoda. Yoda was a wise, experienced, and powerful Grand Master of the Jedi of an unknown species and the oldest known prophet in existence (having lived at least 900 years), considered the wisest and most powerful Jedi Master within the Star Wars universe.
killed by an Imperial strike team, his dark side, like many Seth before him, refused to let go of life.
But the record Sith-killer is actually Darth Bane himself. Darth Bane, founder of the Rule of Two, killed more Sith than any Jedi in the history of the Star Wars galaxy.
As impressive as Vader's battle tactics might be, if he and Revan make a stand with comparable armies, Revan is likely to be victorious. So, this point goes to Revan as well.
Emperor Palpatine/Darth Sidious
Villains like Kylo Ren and Darth Vader sometimes feel the pull to the light, but Darth Sidious, also known as Emperor Palpatine, is the embodiment of pure evil.
Darth Plagueis
Going off what fans know from Legends, though, he is pure wickedness and could be argued as the evilest Sith connected to the Skywalker saga.
The term "Sith Lord" generally encompassed members of both sexes, although some female Sith such as Lumiya, Tahiri Veila, Olaris Rhea, and Vestara Khai were styled Sith Lady. Originally, "Sith Lord" referred to a high-ranking member of the Sith Order's society.
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.
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.
Undermined by constant infighting and ruined by the last war against the Jedi, the Sith were rendered all but extinct with the exception of one; Darth Bane survived the ancient order's destruction and passed his knowledge to a single apprentice, Darth Zannah, before being entombed on Korriban, which became known as ...
He transforms the Galactic Republic into the Empire and declares himself Emperor, using Machiavellian manipulation to invoke martial law. Palpatine rules the galaxy for over two decades before Vader betrays and kills him to save his son, Luke Skywalker.
Emperor Palpatine's "son" was a strandcast cloned from his genetic template. Dathan was an artificially constructed strandcast from the genetic template of Sidious. and the lone specimen that lived through the cloning process.