If you consider yourself a Star Wars fan, but think Darth Vader never took a Sith Apprentice of his own, then you're in for a surprise. As the future of the franchise far, far away is making Darth Vader a more pivotal character in movies, books, comics, and video games, it's time fans did some homework on just how many men, women, aliens, and killers Darth Vader has called his "apprentice."
When Disney purchased the rights to all things Star Wars, many fans were devastated to learn that the movie studio would be wiping the existing "canon" of the Expanded Universe clear, so as to chart a new course free of restrictions or expectations. And that also meant erasing the established Sith Apprentices of Darth Vader, right? Wrong. At least not unless that is explicitly stated. You see, those old stories still qualify as Star Wars Legends, even if they're not canon... yet. But as The Last Jedi hints at Darth Revan still being considered canon, and Solo adds Legends back to Star Wars canon, the trend has been set.
So as the comic books set the stage for Darth Vader to return in future movies, there's never been a better time to brush up on the Apprentices who may also be coming back into the Star Wars universe. Some will be more iconic than others, but one fact is clear: Ahsoka Tano was the only Jedi to call Anakin Skywalker "Master"... but young Sith were a different story.
Galen Marek a.k.a. Starkiller
The hero of the hugely successful Star Wars: The Force Unleashed video game is likely to be the best known apprentice of Darth Vader's, given the honor of being personally blessed by George Lucas himself. He deserves the fame, too, since his story is one of the best ones not to be told in the movies. The child of two runaway Jedi Knights, Galen Marek was spared a similar slaughter by Vader once he had tracked them down, with his strength in The Force too powerful for Vader to ignore. And so, the Sith Apprentice took his own student to one day help him overthrow his own master, Emperor Palpatine.
Galen-- sorry, Starkiller's story from there is known to every player of the game. While the title of 'Sith Lord' was denied Starkiller, along with an official 'Darth' title since he and Vader never succeeded in killing Palpatine, Starkiller is the most formal apprentice in the true meaning of the term. He was so powerful in The Force that even the Emperor tried to claim his over Vader, but in the end (canonically) Starkiller sacrificed himself for the sake of his Rebel allies. Even if the game isn't back in the canon - yet - his family's crest became the insignia of the Rebellion in the game's universe.
Starkiller's Clone, 'Subject 1138'
Never one to let such a perfect apprentice as Starkiller go to waste, it was revealed in Star Wars: The Force Unleashed II that Vader took the remains of his pupil to the cloners of Kamino shortly after the first game's ending. The result was a long line of failed copies, but only 'Subject 1138' (a nice nod to George Lucas' student film THX 1138) proved viable enough to be trained by Vader to nearly identical levels as the original Starkiller. And to be the star of the video game, of course.
The Kaminoan process of memory and training/programming and accelerated aging mean Subject 1138 was a less 'true' apprentice compared to Starkiller's years of study at Vader's side. That said, Vader did see him as having the potential to be just as powerful. Subject 1138's shift towards the light, and not the Dark Side was a flaw to Vader, but may also show he had more of Galen Marek's true nature in him than his Sith Master desired. A problem Vader would address later... because why stop cloning when perfection may be around the corner?
Kharys of Skye
The first non-human apprentice of Darth Vader was actually revealed to Luke, Lei, and Han long after the training had taken place. When the group of heroes wound up on the planet Skye in Marvel's Star Wars Annual: The Long Hunt (1979), they came to learn of the planet and its people's terrifying ruler. She was a winged, female S'kytri who turned out to be a powerful Force user... and personally trained by Darth Vader after the end of the Clone Wars.
As they soon learned, the planet had been in dire need of assistance when three Jedi - Obi-Wan Kenobi, Halagad Ventor, and Anakin Skywalker - arrived to free them from tyranny. When Anakin sensed the Force sensitivity of Kharys, but her years disqualifying her from training (as he had almost been, years earlier) he promised to return. He did so as Darth Vader, training her in the creation and use of a lightsaber, and placing her as the Majestrix of the planet. Sadly, she was vanquished by Luke Skywalker, so no hope of a winged Sith any time soon.
Lumiya a.k.a. Shira Elan Colla Brie
If Starkiller is the truest successor of Anakin Skywalker, then Lumiya would probably be the truest successor of Darth Vader - the half-machine, fascist soldier of the Empire. Those Star Wars fans who are familiar with the novels side of the Expanded Universe will already know Lumiya, and those who don't - learn quick. In no uncertain terms, this Lady of the Sith is one of the most pivotal figures in the legacy of the original legacy of the Skywalker family. And even before she learned The Force, Darth Vader was guiding her on her path.
First as an Imperial operative, fast-tracked through the ranks at Vader's urging before going undercover to oppose Luke Skywalker. When defeat left Shira Brie a broken creature, Vader had her rebuilt in his own image, cybernetically. What she became next is as close to 'a female Darth Vader' in appearance and power as can be found in the Star Wars lore. And as modern writers realized the strength of her story, she grew to further prominence as not only too much of a fighter for any Jedi or Sith to face, but the Shadow Hand of Darth Vader. Oh, and the master who seduced Han Solo and Leia Organa's son to the Dark Side.