"He was a Jedi who wanted to learn to be the greatest one there ever was, but he was overly prideful of his abilities and impatient. He thought his Master wasn't teaching him quickly enough so he began looking into things on his own, some of which his Master knew he wasn't ready for yet. Some of those things involving the Dark Side, which, as you can imagine, his Master never would have wanted up investigating in the first place." Garth'zel pauses for a moment to give Ren time to absorb that.

"His investigations eventually led him to where the spirit of a long-dead Sith was, who promised him power, among other things. He ended up being one of the worst Sith out there. And a fairly effective cautionary tale among the Jedi about the dangers of pride." He wrinkles his nose a moment later. "I really could have done without the creatures he created with Sith alchemy. The Jedi killed a lot of them, but there were still some around by my time, and I imagine there's probably still a few here or there on forgotten or abandoned planets."