Photo Credit: Lucasfilm
Or Kylo Ren could be given an alternate fate.
The possibilities in which the Sequel Trilogy can end are endless as the writers behind these films have full freedom in creating any conclusion they want. When writing Kylo Ren’s fate, the writers could mirror Darth Vader’s arc in the Original Trilogy, ending his arc on a high note, turning back to the Light as well as redemption.
All previous villains in the Star Wars franchise have either died as a villain or turned back to the Light Side and then died. Regardless, all Star Wars villains die at some point or another, an unfortunate fate which Kylo Ren likely will be unable to escape unless he makes a drastic change of heart.
It is fully expected at this point that Ren will remain the villain for the duration of the trilogy, just as his idol Darth Vader did before him.
The main question at this point is whether the story will conclude with him on the Light Side or the Dark Side of the Force, a question that will not be answered until Episode IX hits theaters in May of 2019.
Regardless of all the theorizing and predicting by fans, Kylo Ren has already proven himself to be such a complex and difficult character to read. The number of different routes this character could go are endless.