The Knights of Ren have been mysterious so far in the Sequel Trilogy, only having a shadowy introduction in The Force Awakens. In The Last Jedi, their absence produced the speculation that they could be Luke Skywalker’s fallen pupils.
But a new comic fleshes-out their true origins, that they existed before Ben Solo’s fall to the dark side! See its description:
With the new Jedi school in ruins and fellow students hot on his trail for the murder of their master, Ben Solo flees to the only friend he has left in the galaxy…a man named Snoke. But Snoke has plans for Ben…and ideas about the Force that are as dangerous as they are intriguing for the troubled young Jedi.
If Ben wishes to be truly free…the answers might lie with the dark side. And with the Knights of Ren!
But it won’t be the first time he’s tangled with the Knights. In the past, Jedi Master Luke Skywalker journeys to the Unknown Regions and brings young Ben along for the mission. Can even Luke Skywalker stand against the fabled Knights of Ren?!https://www.cbr.com/marvel-kylo-ren-luke-skywalker-ben-solo-knights-of-ren/
As seen in the cover art, one Knight of Ren has a red lightsaber, and is also absent in the Sequel Trilogy. Perhaps this comic will reveal that he was the original leader who Ben Solo replaced as Kylo Ren.