The Most Powerful Sith In The Star Wars Universe
We're here to talk about the most powerful Sith in the Star Wars universe, but first we have to define what we mean by "powerful." Some among this super-powered clan of mystical space-faring evildoers have wielded powerful magic; others have exerted a lasting impact on the galaxy. Some Sith were more powerful in the ways of the Force than they were influential, while others achieved incredible things despite lacking total command of that wacky space magic. We're going to draw on both definitions to pin down who among the terrifying pantheon of Sith Lords represents the full package of Star Wars villainy.
Darth Bane
Darth Bane is the Star Wars expanded universe's version of a Founding Father when it comes to the Dark Side of the Force. He believed the Sith's organizational structure was deeply flawed. Before he came along, the Sith were much like the Jedi, in that there were a number of masters and apprentices throughout the galaxy, and he set out to condense the number of Sith in the galaxy—all the way down to a final pair. This philosophy was known as the Rule of Two.
Freedon Nadd
Freedon Nadd was a Jedi in the days of the Old Republic, with Force talents far beyond any of his peers. (Remember that sentence, because it's going to be a running theme in this list). While training he became jealous of his Jedi master's power and authority, so in true Sith fashion, he killed him and renounced his affiliation with the Jedi. Nadd traveled to Yavin 4 to be trained in the ways of the Dark Side by Naga Sadow, a Sith lord living in exile who once nearly brought to the Sith Empire to galactic dominance during the Great Hyperspace War.
Marka Ragnos
Marka Ragnos was a Sith Lord who grew tired of their unwillingness to expand beyond their homeworld of Korriban. His reign was ruthless and brutal, laying waste to any and all enemies who dared cross their path—but he didn't always achieve victories through violence. In fact, most of the time, he achieved victory without raising a finger. A master of manipulation, Ragnos set his adversaries against one another, using their mutually assured destruction to clear an easy path for the Sith.
Ragnos lived for over a century, and his story didn't end with his death. As a Force ghost, he pitted two Sith Lords against each other to determine which would be better suited for his vacant seat as Sith ruler, and Naga Sadow won the honor. Ragnos' spirit lingered for some time in a tomb on Korriban until bestowing another Jedi-turned-Sith, Exar Kun, the title of Dark Lord of the Sith. Kun eventually ignited the cataclysmic Great Sith War.
Darth Vitiate
Marka Ragnos recognized this young Force-sensitive boy's potential and gave him the planet Nathema to rule as his own—along with a new name: Darth Vitiate. When Ragnos died, Vitiate chose to not get involved in the battle for his place at the head of the Sith Empire, instead waiting for the perfect opportunity to seize power. That moment arrived in the fallout from the Great Hyperspace War.
Once out of hiding, Vitiate took over the minds of more than 8,000 Sith and forced them to take part in a 10-day ritual that ended with the complete obliteration of Nathema. He absorbed an entire planet's worth of Force energy, thus granting himself immortality, and from that point forward he was no longer Darth Vitiate—he was simply the Emperor.
When the Sith's version of a governing body, the Dark Counsel, conspired to kill the Emperor, he wiped them out in a single blow. He continued to rule the Sith for 1300 years—a reign unmatched in Star Wars expanded universe lore.
Darth Revan
Darth Revan also started as a Jedi who was turned to the Dark Side—in this case, because his superiors refused to indulge his curiosity of all aspects of the Force. He eventually graduated to the rank of Jedi Knight, though he soon found himself at odds with the Jedi Council when they refused to protect the lives of Outer Rim innocents caught in the Mandalorian Wars. Over their objections, Revan assembled at large Jedi defense team that ended up being the main reason the Republic won the war—and ultimately led to his own corruption.
Darth Nihilus
The Dark Side of the Force can be seen as a metaphor for addiction. Once someone with Force sensitivity gets a taste of the Dark Side, they find it immensely difficult to turn back, and they often end up dedicating their lives to it. Darth Nihilus' story offers a literal example of that principle in action: after he was caught in the detonation of a super-weapon known as the Mass Shadow Generator—ordered by Darth Revan—that destroyed the planet Malachor V, Nihilus' body was wrecked, and he was left with an insatiable craving for Force energy. He was, essentially, a force vampire.
Darth Plagueis
One of the running themes in Sith lore is their insatiable thirst for knowledge—knowledge that usually takes those who hold it into dark, morally questionable areas. Darth Plagueis wasn't the most skilled Force user, nor was he particularly good with a lightsaber, or even a tremendous military leader. Instead, Plagueis was a scholar and—if such a thing can be said about a disciple of mystical energy—something of a scientist. He focused his scholarly efforts on a single pursuit: figuring out how to manipulate the Force and midi-chlorians in a way that would allow him to live forever and possibly even bring the dead back to life. If Force users are space wizards, then Darth Plagueis was a space necromancer.
Darth Vader
Before he became Darth Vader, Anakin Skywalker was a Jedi apprentice—until his love for Naboo's Queen Amidala was used by the evil Sheev Palpatine, a.k.a. Darth Sidious, to twist him toward the Dark Side. Sidious poisoned Anakin's mind, turning him against everything Amidala stood for, and even ultimately against his own Jedi Master, the legendary Obi-Wan Kenobi. While Vader never fully lived up to his potential as a Sith (he had the highest midi-chrlorian count ever recorded, after all) he was instrumental in aiding Palpatine's ascent to Emperor. While Palpatine governed mercilessly from the safety of his throne, he had his lackey apprentice Darth Vader to do his dirty work around the galaxy.
Darth Sidious
Darth Sidious' rise to power can be seen as nothing but a masterstroke of the greatest strategic mind in all of Star Wars canon. Taking a note from his master, Darth Plagueis (whom Sidious killed because of that whole Rule of Two thing), he hid in plain sight as a senator who valiantly represented the citizens of Naboo. No one was certain of his malevolent intent until it was too late.
As Palpatine, Sidious clandestinely orchestrated the Clone Wars, which eventually granted him a tremendous amount of political power. His coronation as the all-powerful Emperor of the galaxy was completed with the final phase of his plan: Order 66, a command ordering clone troopers to exterminate all Jedi. In one fell swoop after decades of planning, Palpatine accomplished what every Sith before him had dreamed of, wiping out the Jedi and sending their few survivors into hiding—the same way the Jedi had vanquished the Sith countless times over thousands of years.