Kylo Ren's lightsaber

Kylo Ren's lightsaber was a crossguard lightsaber wielded by Kylo Ren, Supreme Leader of the First Order and master of the Knights of Ren. The lightsaber was previously Ben Solo's lightsaber, constructed by Ren in his life as Ben Solo while training as a Jedi Padawan under his uncle, Jedi Master Luke Skywalker. After destroying the Jedi Temple in 28 ABY, Ren used the dark side of the Force to bleed his lightsaber's kyber crystal, changing the color of its plasma blade from blue to red. However, the kyber crystal was cracked in the process, and as a result, Ren modified his lightsaber by adding lateral vents to either side of the handle in order to divert the extra heat generated by the crystal. His new crossguard lightsaber was based on an ancient design that dated back to the Great Scourge of Malachor.

As a First Order warlord, Ren dispatched his enemies while wielding his lightsaber on the battlefield, such as the Benathy whose homeworld Benath he subjugated after slaying the Zillo Beast they worshipped. He used his saber to kill Lor San Tekka as well as his own father, Han Solo, who confronted him on Starkiller Base in 34 ABY. During the First Order-Resistance War, Ren dueled against the former stormtrooper Finn and the scavenger Rey, and the Elite Praetorian Guard after he assassinated Supreme Leader Snoke. When confronted by his former Jedi Master, Ren challenged Skywalker to a lightsaber duel unaware that the latter had projected his appearance through the Force to the planet Crait, having never departed from his exile on Ahch-To.

In 35 ABY, Ren slew a group of Sith cultists known as the Alazmec of Winsit on Mustafar. He also dueled with Rey through the Force; together they formed a Force dyad, creating a Force-bond that allowed them to fight each other without being in the same physical location. Their last duel occurred in person amidst the Death Star ruins of Kef Bir, where Ren was ultimately turned back to the light side of the Force. Discarding his Sith lightsaber in the ocean, he reclaimed his identity as Ben Solo.

Text and facts from the “Kylo Ren's lightsaber” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.