Let me guess…
The damaged crystal that Kylo Ren uses in his lightsaber was Darth Vader’s crystal that he magically recovered along with Darth Vader’s helmet.
*drum roll*
According to the esteemed wookiepedia I am instantly wrong…
His lightsaber, based on an ancient design dating back to the Great Scourge of Malachor, relied upon a cracked kyber crystal that could barely contain the power of the weapon, necessitating the lateral plasma vents that produced its signature crossguard quillons. The fractured crystal was also responsible for the unstable, serrated appearance of the weapon’s red plasma blades
Source: http://starwars.wikia.com/wiki/Kylo_Ren
BUT
There are no rules remember, this is a whole new story line brought to you by Disney and J.J. Abrams !!! <3
So hey, just you watch as we get something weird thrown at us like the lightsaber crystal being used by villain after villain through the centuries, or that Kylo Ren had to slaughter somebody to harness the power of the crystal, or that the crystal had at one point been Darth Vader’s.
Nooo, it”ll actually be something like… the crystal was originally the one used by Leader Snoke when he was young and the crystal became damaged in some kind of dramatic struggle Snoke had with a rival and his saber was lost.
Kylo Ren then, in his leader worship, resurrected the lost crystal in a new lightsaber.
Sorry guys.
I just feel like Disney and crew are going to come up with something stupid for the backstory of Kylo Ren’s lightsaber.
And it’s exhausting me.