A brilliant scientist, Galen Erso was coerced into using kyber crystals to enhance energy yields – work his friend Orson Krennic then weaponized to create the Death Star’s superlaser. Galen fled to remote Lah’mu with his family, but Krennic tracked him down and forced him to resume his work. Trapped, Galen seeks to build a fatal flaw into the Death Star and reveal it to the Alliance.
The Death Star began as a Geonosian design, but became operational after nearly two decades of work by a team of brilliant scientists sequestered on the rainswept world of Eadu. Led by a reluctant Galen Erso, the Death Star scientists seek to fuse kyber-crystal shards into larger structures and use those crystals to amplify energy into a stable beam powerful enough to destroy an entire planet.
At the heart of every Jedi lightsaber is a kyber crystal found on several planets, most notably the icebound caves of Ilum. This crystal is attuned to the Force, and connected to a Jedi Knight on a deeply personal level. In this way, a lightsaber is an extension of a Jedi's Force awareness. Because Jedi let the Force guide their selection of the crystal, the vibration that the crystal creates in the lightsaber blade helps Jedi center themselves and find balance in the Force. In this way, a Jedi can center his or her attention beyond the distractions of combat. A lightsaber crystal is colorless until first attuned and connected to a Jedi -- at which times it glows either blue or green, or in some rare instances, another shade. From that point on, it retains that hue.