https://www.ign.com/articles/2019/10...knights-of-ren

Curious thing here, that Ben and Luke fought the knights before he went down the dark path.


....also, this seems to partially explain what happened to at least some of Luke's other students who Luke said were missing-they presumed he was dead and took off after Kylo left and the Knights. I'm guessing their journey to "avenge" Luke didn't go to well.