In a sense, the Jedi and the Sith are different sides of the same coin in the Star Wars universe.
The Jedi believe in control over themselves, their emotions, and control in everything else in the Star Wars Galaxy through peace.
The Sith, on the other hand, believe in power; power to shape the Galaxy as they see fit. And while the Jedi believe that anyone should have the power of control over their lives, the Sith believe that anyone should control the amount of power they can individually achieve.
Now, there is a fine line between power and control, and in moderation, neither of them are evil. What makes the Sith evil, because all of them are, is the Dark Side of the Force.
While the Light Side is channeled with feelings like serenity, honesty, empathy, and love, the Dark Side is accessed through fear, anger, hate, envy, and suffering. These negative emotions, further fueled by the Dark Side itself, are what make the Sith both so powerful, and extremely dangerous.
Count Dooku / Darth Tyranus
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.
Revan
Revan is a fictional character in the Star Wars franchise. He was created for BioWare’s 2003 role-playing video game Star Wars: Knights of the Old Republic, in which he is the playable protagonist.
Darth Bane
Learn the story of Darth Bane. The biggest, baddest Sith to ever walk the Galaxy. The creator of the Rule of Two and the “father” to the lineage that would bring about the end of the Jedi. Bane is actually canon after his appearance in The Clone Wars, but most of history so far is Legend.
Darth Nihilus
The story of Darth Nihilus is one paved with great suffering and pain but also immense power, Darth Nihilus grew to become one of the most powerful Sith lords in all of Star Wars and today we will explain how and why his story ultimately ended.
Darth Plagueis
Learn the story of Darth Plagueis the Wise: the master of Darth Sidious, and seeker of eternal life. His experiments in the dark side with Darth Sidious inadvertently caused the creation of Anakin Skywalker.
Vitiate
Tenebrae known to the Old Sith Empire as Darth Vitiate, his reconstituted Sith Empire as the Sith Emperor, and his Eternal Empire as Valkorion—was an ancient dark side entity of enormous power who manipulated galactic affairs for 1,500 years.
Darth Sion
Darth Sion, the Lord of Pain, was a Sith Lord who lived in the time of the Old Sith Wars. 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. With a body fractured and decomposing, but held together by the dark side of the Force, Sion survived the Great Sith War.
Darth Vader
Discovered as a slave on Tatooine by Qui-Gon Jinn and Obi-Wan Kenobi, Anakin Skywalker had the potential to become one of the most powerful Jedi ever, and was believed by some to be the prophesied Chosen One who would bring balance to the Force.
Darth Sidious
Scheming, powerful, and evil to the core, Darth Sidious restored the Sith and destroyed the Jedi Order. Living a double life, Sidious was in fact Palpatine, a Naboo Senator and phantom menace.
Tulak Hord
Tulak Hord, known as the Lord of Hate and Master of the Gathering Darkness, was a Dark Lord of the Sith that ruled during the early Sith Empire, commanding great armies and possessing a mastery of the dark side of the Force and lightsaber combat which left him nearly unrivaled.