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, the Jedi Master Luke Skywalker. Originally the weapon had a blue blade, but after his destruction of Luke Skywalker's Jedi temple and fall to the dark side in 28 ABY, Ren modified it into one with a red blade. The modified lightsaber incorporated a crossguard hilt based on an ancient design dating back to the Great Scourge of Malachor and 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.