It's no secret that the Star Wars universe, which is composed of the current canon and Legends, is massive. Authors, filmmakers, and video game developers have been telling stories set in the galaxy far, far away for decades. Amid all that content is a diverse selection of antagonists that are awfully underutilized.
Given the wealth of material available in the Legends continuity, there exist several villains who are ripe for further exploration. Some fans may have never even heard of these characters, considering many of them have been somewhat forgotten over the years. These Star Wars villains definitely deserve more attention in the grand scheme of things going forward.
6 Ajunta Pall
The origin stories of both the Jedi and Sith make for interesting reading. Although the Old Republic era has been given a lot of attention, Star Wars' ancient history offers fertile ground. One villain that deserves some limelight is Ajunta Pall, a fallen Jedi who became the first Dark Lord of the Sith.
Ajunta Pall was a Jedi Master who split from the Order, playing a key role in a civil war known as the Hundred-Year Darkness. Pall and his followers were defeated and forced to flee. They discovered Korriban, a desert planet populated by a strange alien species called "Sith." The Sith worshipped Pall and his followers as gods. The two groups interbred with each other over generations, spawning a hybrid species that proved strong in the Dark Side of the Force.
Ajunta Pall makes a brief appearance in Star Wars: Knights of the Old Republic, where his spirit can be encountered by the player character on Korriban. Giving this villain more time to shine represents some rich storytelling potential if handled properly.
5 Prince Xizor
Many Star Wars fans are likely familiar with Jabba the Hutt, the galaxy's premier crime lord in the original films. However, the galaxy is filled with more criminal elements than just the Hutts. One organization that was featured sporadically in the old Expanded Universe was the Black Sun crime syndicate.
The syndicate was led by Prince Xizor, an enigmatic Falleen who wielded an immense amount of influence. He was featured prominently in Steve Perry's acclaimed novel, Shadows of the Empire, where Prince Xizor attempts to assassinate Luke Skywalker. Prince Xizor is a prime example of a cunning criminal: cold, calculating, and utterly ruthless in his illicit dealings.
4 Warlord Zsinj
The Imperial Civil War is one of the most interesting aspects of the Legends continuity. After Palpatine's death, the Empire breaks apart into mini-kingdoms, each ruled by an influential member of the New Order's elite. One of the more successful (and outlandish) examples of these opportunistic leaders is Warlord Zsinj.
Magnificent mustache aside, Warlord Zsinj proves to be a dangerous thorn in the side of the fledgling New Republic. He captains the Super Star Destroyer Iron Fist, which he uses to great effect in carving out his own empire. Warlord Zsinj appeared in several written works, but most prominently in The Courtship of Princess Leia novel. Giving this wily foe more attention would be a breath of fresh air.
3 Darth Zannah
When it comes to excellent Star Wars reading material, it's hard to beat Drew Karpyshyn's Darth Bane trilogy of novels. There's certainly an argument to made that the character of Darth Bane himself should be given more attention. Nevertheless, giving Bane's apprentice, Darth Zannah, some of the limelight is also compelling.
Her backstory is interesting: As a little girl, one of Zannah's friends was killed by Jedi, whom she slew in a fit of rage. Sensing her anger, Darth Bane discovered her and decided to train Zannah as his apprentice, instituting the "Rule of Two." Although Zannah eventually succeeds Bane as the Dark Lord of the Sith, the details of her exploits afterward could be expanded on.
2 Lumiya
Like the other entries on this list, the character of Lumiya, Dark Lady of the Sith, represents a lot of creative potential. Once known as Shira Brie, Lumiya was an Imperial spy sent by Darth Vader to infiltrate the Rebel Alliance. Her assignment, however, went horribly wrong, leaving her disfigured and close to death.
Similar to her mentor, Darth Vader, Brie was given cybernetic prosthetics that not only saved her life but also gave her a fearsome-looking appearance. Armed with a Lightsaber whip, Lumiya studied the ways of the Sith throughout the succeeding decades. She caused a lot of grief for the New Republic as well as the extended Skywalker-Solo family.
Lumiya killed Luke Skywalker's wife, Mara Jade, and also turned Han and Leia's son, Jacen, to the Dark Side. Lumiya fell to the wayside when the new Star Wars canon was introduced, which is a shame considering her prominence in the later Legends timeline.
1 Marka Ragnos
It was stated earlier that Star Wars' ancient history possesses a lot of untapped potential. Exploring any of the older Sith Lords in more detail would be interesting. One of the prime contenders would have to be Marka Ragnos, a powerful Dark Side-user whose reign is often referred to in the lore as the "Golden Age of the Sith."
Marka Ragnos was descended from one of Ajunta Pall's followers. He was one of the Sith Order's wisest and most respected Dark Lords, who ruthlessly eliminated his rivals and solidified the borders of his empire. Surely, his life represents fertile ground for any talented writer, filmmaker, or video game developer.