Kylo Ren (aka Ben Solo), the petulant, patricide-loving baddie who takes over for Darth Vader in Episode VII, is a complicated character, to say the least. As the son of Leia Organa and Han Solo (the latter of which he later kills, RIP), it's explained that Kylo trained in his uncle Luke's Jedi academy, only to later be convinced to cross to the Dark Side of the Force and murder the rest of Luke's Padawans and go after Luke himself. He's portrayed as being evil, but very unstable, prone to flying off the handle at a moment's notice and deeply questioning his faith to the Dark Side ("I feel it again. The pull to the light."). Because of these incongruous personality traits, there's a theory floating around out there that suggests Kylo is actually a good guy, whose grand plan is to infiltrate the First Order from within so he can kill Supreme Leader Snoke.
Good or bad, it seems likely that we're going to get a definitive answer about his true motives in the next movie, if only because there's only so many innocent people Kylo can continue to kill until he passes over to the Dark Side for good.
