Naga Sadow perhaps the most ambitious among them he started the Great HyperSpace War,

Exar-Kun, a direct descendant of Nadd, a fallen Jedi who became a Dark Lord, started one of the new Sith Wars in the Old Republic era, his spirit still haunts Yavin

Darth Revan, both Jedi & Sith yet neither at the same time, a person of worthy of wearing the mantle of the Sith'ary, one of the greatest Sith Lords to have ever loved, his history alone reshaped the Galaxy 3 times over, from the Mandalorian Wars, to the Jedi Civil War & its aftermath all the way to Cold Wars, the New Sith Wars during the Dark Ages, so great was his legacy, his military tactics lead to the foundations of modern-day Galactic Republics Military hen the Imperial Army, his legacy had a profound impact on the Jedi but mostly for the Sith he was their greatest revolutionist & renaissance man, his teachings would lead Darth Bane to the Creation of the rule of Two! His mask is the Coruscant History Museum from Orbit

Darth Bane, the second Sith'ary, he who lead the Sith to new power, destroyed the Brotherhood of Darkness & build the legacy for the modern day Sith we know, under the teachings of Revan's Holocron he would create the Rule of Two



If we were to take notes on some of greatest to have ever lived then we have this,King Adas, the First Sith Lord the Original Sith'ary Greatest of the Dark Lords to rise a true literal God-King among his people,Tulok Horder first of great ancients whos legacy and teachings are still used by the Sith a master of the lightsaber and duelist without pears so strong was his connection with Dark Side of the Force he could tear out ships from the sky,Marka Ragnos Greatest among the Dark Lords and one of the most powerful ancients to have ever lived with a reign of a full century during his rulership of the Golden Age the Sith flourished his soul survived even Death its self,Freedom Nadd perhaps the most dangerous amongst the Sith, power-hungry and complete butcherer,