We know that Kylo is obsessed with the Sith of the past, primarily his grandfather. However, since Snoke appears more interested in Rey than Kylo at the end of TFA, perhaps Kylo will eventually find himself cast aside by Snoke or himself become disillusioned when he discovers that Snoke isn’t a Sith. If this is the case, he could devote his energy to uncovering the secrets of the first Sith, and his journey would be a dark parallel to Luke’s in wanting to find the first Jedi temple. They, along with Rey, would meet at the place where the Jedi and Sith broke into two factions, and the three would have an explosive confrontation, eventually culminating in an apotheosis where they reconcile their differences and turn to confront Snoke.