Kylo Ren's lightsaber

Kylo Ren's lightsaber was a crossguard lightsaber constructed by Kylo Ren, an agent of the First Order, sometime before or during 34 ABY. The lightsaber, based on an ancient design dating back to the Great Scourge of Malachor, contained a cracked Kyber crystal, requiring it to have lateral vents on either side of the handle in order to divert the extra heat generated by the crystal.

During the cold war, Ren wielded the lightsaber to kill Church of the Force member Lor San Tekka, and his father, Han Solo. He later dueled the former stormtrooper known as Finn, and the Force-sensitive scavenger Rey, though he lost to the latter.

Description
Kylo Ren's lightsaber was the personal crossguard lightsaber of Kylo Ren, an agent of the First Order serving as Master of the Knights of Ren. The weapon was built sometime before or during 34 ABY. The lightsaber was crudely assembled based on an ancient design dating back thousands of years to the Great Scourge of Malachor. Despite being an ancient design, the lightsaber had modern components inside it. A single cracked Kyber crystal, barely able to contain the weapon's power, necessitated the lateral vents which diverted the extra heat produced by the crystal to either side of the hilt, and gave the weapon's red plasma blades an unstable, serrated appearance. To balance the weapon's power, the crossguard blades emerge after the main blade appears.

History
"Ben!''" "Han Solo. I've been waiting for this day for a long time. [...] Will you help me?" "''Yes. Anything."

- Han Solo and Kylo Ren

Ren wielded the crossguard lightsaber while working alongside the Knights of Ren and the First Order. During the conflict between the First Order and the Resistance, he used the lightsaber to kill Lor San Tekka, a member of the Church of the Force, as well as his own father, Han Solo. It later crossed blades with the lightsaber that formerly belonged to Ren's grandfather, the Jedi Knight Anakin Skywalker. Although he defeated and injured the former stormtrooper known as Finn in a brief duel, he was in turn defeated by Rey, who successfully channeled the Force within herself to fight back, striking Ren's lightsaber and knocking it from his hand.

Sometime later whilst in the presence of Supreme Leader Snoke's Elite Praetorian Guards, the lightsaber came into the possession of Rey.

Behind the scenes
Kylo Ren's lightsaber was introduced in the first teaser trailer for Star Wars: Episode VII The Force Awakens. The trailer, released on November 28, 2014, showed Ren walking through a snowy forest on Starkiller Base and igniting the lightsaber. The introduction of the lightsaber was well-publicized in the media, including on The Colbert Report and @Midnight on Comedy Central. The lightsaber was also the subject of a number of pieces of fan art released in the days after the trailer premiered.

It appeared twice in the second trailer that debuted at Celebration Anaheim 2015. The trailer showed Ren swinging the lightsaber, and later holding it in his left hand while he holds out his right. The concept of a crossguard lightsaber was first introduced in Star Wars Legends, previously known as the Expanded Universe. The lightsaber, which had two beams rather than three, made its first appearance in the 2004 comic book Republic 61: Dead Ends.

Appearances

 * Star Wars Battlefront II
 * Star Wars: Episode VII The Force Awakens
 * Star Wars: The Force Awakens novelization
 * Star Wars: The Force Awakens: A Junior Novel
 * Star Wars: The Force Awakens Graphic Novel Adaptation
 * The Force Awakens, Part I
 * The Force Awakens, Part II
 * The Force Awakens, Part IV
 * The Force Awakens, Part V
 * The Force Awakens, Part VI
 * The Force Awakens: Rey's Story
 * Star Wars: The Force Awakens Beginner Game
 * Captain Phasma, Part I
 * Star Wars: Episode VIII The Last Jedi
 * Star Wars: Episode VIII The Last Jedi

Non-canon appearances

 * Disney Infinity 3.0
 * LEGO Star Wars: The Force Awakens
 * Star Wars: Galaxy of Heroes