The Sith Empire is the darkest and most ruthless force in the galaxy. From their very inception, they've always desired every form of power that exists within the Force and are willing to kill whomever they need to in order to get ahead. They've been trying to conquer the galaxy far, far away for what seems like forever now.
In order to take over the universe, the Sith are constantly employing new methods of combat and Force powers in order to do so. As time goes on, the Sith become darker and darker until they are turned into unfeeling, corrupt monsters that give nightmares to little children. The arts that these corrupted Jedi are willing to uncover contain some of the most unspeakable evils in all of Star Wars.
Since their introduction, we've constantly been learning new things about the Sith. While many of these stories are no longer canon and are now part of Star Wars Legends, there is still much we can glean from what is considered canon and what isn't. The Sith have hidden many dark secrets over the years, and while many of them are still buried, many of them have come into light for all to see. And sometimes, when things used to darkness come into the light, they destroy everything in sight.
If you're willing to delve in the darkest facts in Star Wars, then continue on to read about 15 dark secrets of the Sith.
15 Not All Dark Force Users Are Sith
Now here is a clear distinction that must be made. Just because a Jedi goes bad doesn't automatically make him a Sith. The Sith are a clear faction of Force users and officially take on new apprentices in order to train them in the ways of the Dark Side. If they don't fall into this category, then they themselves are not Sith. This has led to a lot of confusion among the Star Wars fans, but it begins to make sense if you delve a little deeper.
For example, it would be incorrect to label Kylo Ren a Sith. While he is a great supporter of Darth Vader and knows the ways of the Dark Side, he is not officially a Sith. Instead, he is labeled as a Dark Jedi. Basically any fallen Jedi that isn't a Sith earns this title. Dark Jedi are willing to pursue the Dark Side of the Force, but don't align themselves with the Sith Empire or Galactic Empire, etc. They simply dislike the ways of the Jedi and decide to pursue their own path through the Force. Qui Gon Jinn's first apprentice traveled down this path.
14 They Often Killed Each Other
Back when the Sith were first introduced, the idea was to be able to directly combat the Jedi. In order to do this, they decided to induct as many Sith into their order as possible, attempting to outnumber their heroic counterparts. While this worked for a time, it wasn't long before the problems began to seep through the cracks.
The biggest issue is that all Sith essentially desire power. This led them to kill one another in order to increase their rank. Because of this, Sith leaders were constantly in rotation and on their guard. Just when you though some Dark Lord was taking control completely, someone killed them and took their place. When we really think about it, it's not exactly the most effective way of running an organization or preparing to fight all of the Jedi. This resulted in a lot of wars within the Sith Empire itself, and the problem became so severe that having so many Sith exist at a time was done away with altogether. They have Darth Bane to thank for that, considering that he introduced the Rule of Two. Speaking of which...
13 The Rule of Two Still Results in Death
After Darth Bane was present in a brutal Sith war, he became the leader of the dark empire and proposed the Rule of Two. This rule stated that only a Sith master and his apprentice could exist at a time -- a master to embody the power of the Dark Side of the Force, and the other to crave it. While this has proven to be effective throughout the saga and Star Wars Legends, it still comes with its own share of problems.
Because of the nature of the Rule of Two, it is still designed to promote betrayal and killing. The only way a new apprentice is inducted is if the current apprentice kills the master or the master kills the apprentice. Because the Sith inherently desire the power of the Dark Side, they often ally with each other, but only until the opportune time for murder comes. Example: Darth Sidious ended up killing his master Darth Plagueis and his apprentice Darth Tyranus. There are numerous other examples of the Rule of Two ending in betrayal, but what's more twisted about this is that the Sith were designed this way -- apprentices and masters being encouraged to kill one another.
12 Supreme Leader Snoke Is not a Sith
This goes along with my first point. Supreme Leader Snoke has proposed the most questions and theories out of any of the Star Wars movies to date, and I'm about to throw another wrench into the speculation: Supreme Leader Snoke is not a Sith Lord. If he were, then Kylo Ren could be considered his Sith apprentice, but he's not. This proposes all kinds of further questions about the character. What are his motivations? Is he Force sensitive? How does he factor into the later films then?
According to J.J. Abrams, Snoke felt that the Sith were very inefficient due to them killing each other even with the Rule of Two. Because of this, he himself did not become a Sith; he just uses the Dark Side of the Force to accomplish his goals and defeat his enemies. He not only seeks to be different from the Sith, but also seeks to surpass them entirely, having much bigger and better plans to take over the galaxy than any of his predecessors ever did. Only time will tell what this means for Kylo Ren and the Knights of Ren themselves, but here's hoping that it's awesome.
11 The Sith Empire was Formed By Jedi
Every story has its origin, and the same is true of the Sith. When the Jedi were originally created, they set rules and guidelines for themselves. They were aware that the Force had a Dark Side, which they heavily encouraged their comrades not to pursue, even going so far as to make it forbidden. However, without a proper explanation of why, some Jedi were bound to be tempted by the different abilities.
Actually, a group of Jedi felt that the rules were a bit outdated and that they'd never be able to reach their full potential without pursuing all sides of the Force. Thus, they dabbled in the Dark Arts and were expelled from the Jedi Order, giving birth to the Sith Empire. From the beginning, they desired power and put no limitations on themselves in regards how much of the Force they could tap into. Soon, the Jedi found that they were highly outmatched because the Sith were so willing to channel all kinds of unique and deadly abilities. Unfortunately for the Jedi, the philosophy of the Sith would remain so prevalent that other Jedi would continue to fall into the path of the Dark Side.
10 Lightsabers Are Built from Enemy Blood
Now don't take this literally. The Sith don't collect blood in a vial and pour it into a handle to create a lightsaber. What this really means is that all lightsabers are created from Kyber Crystals, which have all sorts of different colors like blue, green, purple, etc. The color of the crystals dictates the color of the lightsabers built with them. Many Jedi specifically chose the Crystals that they wanted when constructing their own lightsabers, but the Sith have a much different motto.
Depending on which story you look at, you'll get two different origins to the red lightsabers. One of them is that the Sith used synthetic Kyber Crystals that were much stronger than the real ones. This way, their lightsabers would be much more powerful than the Jedi ones. (This origin is the one that is canon). Another origin is that the Sith would kill a Jedi and damage the Kyber Crystals in the Lightsaber as a result. Because the Crystals were damaged, they would "bleed" and become red. The Sith would then use the new red lightsaber they picked up from their foes as a way of mocking the Jedi.
9 Sith Spirits Live On
The afterlife is a bit unspecific in Star Wars, but we do know a few things about the Sith. For one, the legacy of a Dark Lord of the Sith can go on for so many years that the hatred and power of the Dark Side itself can manifest into a spirit. These Sith spirits have existed on many planets, and while they're not the real versions of the villains they represent, they are still evil beings and will attempt to persuade anyone to the Dark Side.
Some of these spirits existed on the Sith home planet Korriban, where Master Yoda encountered a few himself. Sometimes these spirits can attack and have a physical form. One such example lies in a cave on Dagobah, as seen in Empire Strikes Back. This cave was reportedly filled with energy from the Dark Side and could create a form reflecting the greatest foes of any person. For this reason, Yoda faced Emperor Palpatine, and Luke came into contact with Darth Vader. These Sith spirits have been known to live on years after the death of a respective Dark Lord, but they have little bearing over the physical world. That said, they should never be underestimated.
8 The Death Star was an Ancient Sith Design
Back in the Golden Age of the Sith, the fallen Jedi knew how to create advanced weaponry through their connection to the Dark Side and their technological prowess. Many different weapons were invented at the time, including the powerful Sith swords. One weapon that was thought of in concept was the Death Star. However, the Sith Empire largely diminished before this idea ever came into fruition.
Later, Darth Sidious discovered this old design and decided to take it to the Geonosians to perfect. From there, work was begun on this deadly space station that could destroy planets. The Death Star functions on a single fundamental principle: what would a giant lightsaber be like? The station is powered with an astronomical amount of Kyber Crystals, which give the machine its green laser. The size and sheer volume of the crystals make the laser so powerful that it can instantly cut through planets within a matter of seconds. It is quite interesting that the Sith decided not to use the synthetic Kyber Crystals for the Death Star (considering the greater power and all), but perhaps that was later implemented in the Starkiller Base. (That laser was red).
7 A Sith Temple Lies Under a Jedi Temple
Back when the Sith were too numerous to count, they built all kinds of temples to counteract the temples constructed by the Jedi. After the Rule of Two had been implemented and most of the Sith had been wiped out, the practice of maintaining these temples was done away with. However, remnants of these dark structures can still be found across all corners of the galaxy, but the most interesting one lies right in the Jedi's back door.
The Jedi have many active temples themselves, but the central one was built on the planet Coruscant. The interesting thing about this temple is that it was built on top of an old Sith temple. The reason for this was that the Jedi conquered the Sith temple and built their own over it as a symbol of victory. The irony of it all is that Darth Sidious actually used the presence of the Sith temple as a way of clouding the Jedi Council's mind when he began infiltrating the Republic. Looks like, once again, it was the pride of the Jedi that led to their downfall.
6 Anakin Skywalker Was Created by a Sith
During The Phantom Menace, Qui Gon Jinn and Obi Wan Kenobi come across the desert planet of Tatooine. It was there that they came across Anakin Skywalker: a brilliant young boy who had no father. According to his mother, he simply appeared in her womb one day. After some examination with the midi-chlorians, Qui Gon felt that this boy could fulfill the legendary Jedi prophecy. After all, it seemed logical to believe so after a Force-sensitive child was conceived with no male influence.
However this was simply a ruse by Darth Plagueis. You see, Plagueis had become a master of life and death after being obsessed with immortality. He and his apprentice, Darth Sidious, hatched a plan to take over the Republic. In order to do that, Plagueis decided to create a Force-sensitive life that they could use to become a future Sith. By manipulating midi-chlorians, the Dark Lord created Anakin Skywalker in his mother's body to trick the Jedi into thinking that he was part of a prophecy. This makes it all the more shocking that the Jedi Council never once detected this. Sure they didn't want Skywalker trained, but it wasn't for those reasons.
5 The Sith Is Also a Cult
The Sith Empire drastically changed once Darth Bane employed the Rule of Two. No longer were these fallen Jedi an empire -- rather, they were a few individuals who craved the power of the Dark Side of the Force. However, they had no shortage of followers over the years. As a matter of fact, many people (both Force sensitive and non-Force sensitive) believed heavily in the teachings of the Sith and began following them religiously. This is what turned an aspect of the Sith into a cult.
Numerous people pursued the teachings of the Sith and were willing to take down the Jedi, despite not actually being Sith themselves. This kind of motivation, however, inspired some of the most powerful villains of the Star Wars universe. The most notable example is Kylo Ren, who admired the Sith and his grandfather, Darth Vader, and became a brutal villain of the Resistance as a result. This cult was heavily modeled after a form of demonic worship and contains a lot of sadistic rituals and practices as well. I'm not sure what would persuade people to join a cult of such darkness...
4 Only One Sith Apprentice Left the Empire
In all of the stories of the galaxy that have been recorded, all of the Sith apprentices have either died or taken the position of their masters. Count Dooku was killed by Anakin, Darth Vader and Darth Sidious were killed simultaneously, Sidious killed Plagueis, etc. The Sith heavily embody the Rule of Two, and people who fervently pursue this path of the Dark Side don't simply leave it. That being said, there was only one apprentice who left the Sith and remained alive: Darth Maul.
As you probably remember, Darth Maul was the villain in Episode I and was cut in half by Obi Wan Kenobi at the end of the film. While he was presumed dead, it was later revealed that he survived the fall and operated for many years. Gaining a set of robotic legs, Darth Maul became a brutal warrior and still trained in the ways of the Dark Side. Later on, he would make his triumphant return in Star Wars Rebels as a neutral party of sorts. Despite his fluency in the Dark Side, Darth Maul had the new desire to kill Darth Sidious as well as get his revenge on Obi Wan.
3 They Can Kill With a Look or a Thought
The Sith have an immediate advantage over the Jedi simply by having access to abilities from both sides of the Force. The Dark Side, incredibly dangerous, boasts some of the most impressive Force powers ever used by a Force-sensitive person.
One of these amazing abilities is Force Kill. All a Sith has to do is leave their hand in the air and think about killing someone. The victim's organs slowly begin to collapse, and a burning pain is felt by the poor soul until he drops to the ground in death. It is one of the most painful ways to go and one of the more impressive abilities used by the Dark Lords.
That's not the only thing they can do though. A Sith also has access to Deadly Sight. Deadly Sight takes up a lot of energy and power, but it can yield some truly damaging results. All a Sith has to do is look at multiple people and concentrate. Within seconds, the targets will immediately burst into flames and writhe in pain before they succumb to their wounds. Moral of the story: don't mess with a Sith.
2 Any Jedi Can Easily Turn
A lot of people think of the Star Wars sides as very black and white concepts. You're either good or you're bad. Thus, the choice of which side you want to go to seems crystal clear. Unfortunately for the Jedi, the options aren't quite that simple. There are more things at play when a Force user decides which side of the Force they want to use.
First of all, understand that the Jedi have very strict rules. This isn't inherently a problem, but when padawans have questions about the Dark Side, the older Jedi should be willing to answer. It is often this curiosity, however, that leads young Jedi on a path of discovery until they stumble upon the allure of the Dark Side. From there, the fall happening is only a matter of time.
Thus, the Sith, before they were Sith, weren't predestined to be evil. Some of them simply wanted to acquire more knowledge about the Force and the universe itself. Because the Jedi were so limited, many felt that they couldn't truly embrace their Force abilities. Due to this fact, any Jedi can actually succumb to the beautiful freedom that exists within the Dark Side of the Force -- even the greatest masters.
1 They Cannot Become Force Ghosts
Now here's an interesting detail. Ever since Return of the Jedi, we've been faced with the concept of Force ghosts. We've seen Obi Wan, Yoda, and Anakin Skywalker all use this power. But how does it work? Well, much like the Dark Side has exclusive access to some powers, so too does the Light Side. In fact, one of their greatest abilities is the gift of immortality. While their physical forms can still die, their spirits can live on in the world. And unlike the Sith spirits, Jedi force ghosts are actually the souls of the people they represent. This allows a Jedi to essentially become immortal and was a trick unlocked by the rebellious Qui Gon Jinn.
Sith don't have access to this ability. This is why Lords like Darth Plagueis became so obsessed with increasing their lifespan. Because Sith's souls died when their bodies did, they had to figure out some way of leaving a lasting legacy and survive beyond death. A proper way hasn't been fully discovered by the Sith though, and no matter how hard they try, they will likely never become Force ghosts like the Jedi. This seems to be absolute confirmation that Darth Vader became a Jedi in his final minutes.
Sources: Starwars.com, Wikia