Killing Han Solo wasn’t the catharsis Kylo Ren was looking for. So, if Kylo Ren’s journey in The Force Awakens was all about his attempt to transcend his former identity – Ben Solo – and embrace the dark side, The Last Jedi appears to represent his inner conflict surrounding the consequences of his actions. On a more visual level, the scene in the trailer where Kylo smashes his helmet against the wall might further support this idea.