If you've always wondered why bad guys use red lightsabers in "Star Wars," a new expanded universe novel has got your answer. Author E.K. Johnston's new novel "Ahsoka," which stars Anakin Skywalker's fan favorite padawan from the "Clone Wars" and "Rebels" animated series, clears up the red lightsaber question with a bloody answer.

Among the many big continuity reveals Screen Rant found in the novel, one about the kyber crystals clears up a bit of Jedi/Sith lore. The crystals are used to power weapons in the Star Wars universe, including the Death Star and -- of course -- lightsabers. These special crystals reveal themselves to the Force users that they choose. Since no kyber crystals reveal themselves to the Sith, that means that the dark Jedi users have to steal them in order to power their lightsabers. And when a dark side Force user powers up a kyber crystal, the novel says the crystal "bleeds -- thus making red the only color it can produce.

Kyber crystals can be found in a select number of locations, with Jedha -- the planet described by "Rogue One" director Gareth Edwards as the Jedi Jerusalem -- being a prominent source. Considering that the crystals are also tied to the Death Star, it's possible that the Empire's occupation of Jedha as seen in the upcoming "Rogue One" film will be because of kyber crystals.

Ahsoka Tano, known in her youth by the nickname "Snips," is a member of the Togruta species and learned under Anakin Skywalker as his padawan learner during the Clone Wars. Voiced by Ashely Eckstein, the character debuted in the 2008 "Star Wars: The Clone Wars" animated feature has become a mainstay of "Star Wars" animated series and amassed a large fanbase. The novel "Ahsoka" reveals more about the Jedi's history as well as more glimpses at her life in the era of "Star Wars Rebels." Additionally, "Ahsoka" dives into more of what Obi-Wan Kenobi was up to during his time on Tatooine in-between "Revenge of the Sith" and "A New Hope."

"Ahsoka" is on sale now. "Rogue One: A Star Wars Story" arrives in theaters on December 16.

(via Uproxx)