Kyber crystals. Before Rogue One: A Star Wars Story, they were probably not in your lexicon (and might not even be after it). Sure, if you watched Star Wars: The Clone Wars or Star Wars Rebels, you might be a bit more familiar. The Rogue One prequel novel Catalyst, the young adult novel Ahsoka, and the just-launched Darth Vader series set directly after the ending of Star Wars: Revenge of the Sith continue the expansion of knowledge. So why are Kyber crystals suddenly so front-and-center in Star Wars, and what does it mean for Rey (and her lineage) and Kylo Ren going forward, especially Star Wars: The Last Jedi?

Kyber 101

Kyber crystals are best known as the small crystals that power lightsabers. A commonly explored item in the old Expanded Universe, they didn’t get the official canon name of Kyber until Star Wars: The Clone Wars season 5, episode 7, “A Test of Strength.” In that story arc, centered on younglings in that era, they travel to Ilum, where Kyber grows in abundance in caves. This is when we first learned of the crystals themselves having some sort of resonance in the Force. Indeed, the crystals call out to individual Jedi, bringing them to the crystal. Thus begins the bonding between a Jedi and their lightsaber, and shows why some have different colors of blades, or wield two or a double-bladed saber instead of one. It’s the Kyber crystals, and the Force, that willed it that way.

Thanks to more recent books, we’ve learned that their resonance in the Force is even more pronounced than the show revealed. Remember when Chirrut Îmwe knew Jyn had a Kyber around her neck, despite him being blind, her having it tucked into her shirt, and being across a busy street? Yup, that’s because it “talked” to him through the Force.

Kyber crystals are most commonly found in small sizes used for lightsabers, but they’ve also been used to power weapons of mass destruction throughout the ages. The Sith constructed superweapons using Kyber, like the one on the planet Malachor that also used a Sith Holocron to unlock it, and of course, the legendary Death Star’s superlaser was powered by Kyber crystals (thanks to the research of Galen Erso). In the Sequel Trilogy era, the First Order has weapons in some of their Star Destroyers powered by Kyber – using crystals taken from somewhere in the Unknown Regions (click that link for another deep dive).

What Kyber Wants, Kyber Gets…

Kyber being a near-living and near-conscious material is central to the recent writings and stories about it. Nothing has been as revealing, perhaps, as the novel Ahsoka and the first issue of Darth Vader from Marvel Comics, both of which detail how a dark side user’s Kyber crystal turns red. You see, they don’t start that color and dark siders would actually have a hard time wielding a lightsaber powered by a regular Kyber for very long. Instead, they need to use the dark side of the Force to overpower the crystal, and dominate it into serving them. That makes crystals bleed into a dark red. Furthermore, a Sith Lord is meant to not simply convert a Jedi crystal that they used before turning to the dark side (both Count Dooku and Anakin Skywalker served the Jedi Order before they served Darth Sidious, after all). Instead, they must take a Kyber from a fallen foe, and dominate that to power their crimson blade. Mostly for extra darkness. Note, in the old Legends continuity, Sith blades were powered by synthetic crystals, causing their color. The new explanation is way cooler.

However, Kyber crystals still want to be on the light side, and can be purified. When Ahsoka Tano was on the run from the Empire during the early years of the dark times, she heard the call of a pair of kyber crystals – the ones in the spinning double-blade of the Inquisitor called the Sixth Brother. The crystals called out to her, choosing her, and wanting to be pure once more. When she defeated and killed him, she acquired his crystals. Taking away the dark side energy caused them to revert from the blood red to a clear white, resulting in her unique lightsabers as we see in her appearances in Star Wars Rebels.

Interestingly, when Sidious and Vader defeated the Jedi order, killing the vast majority with Order 66, it wasn’t enough to simply kill the light side Force wielders. They also collected most of their lightsabers and destroyed them in a kiln; the resultant explosion of light side Force energy flew high above the former Jedi Temple, which further shows how they’re connected directly to the Force. It also seems to imply that their inherent connection to Jedi (and the fact they could potentially “call out” to other burgeoning Force users) was considered a threat by the Emperor.

But what does all of this mean for Rey and Kylo Ren? Let’s dive in.