Kylo burned down the Jedi temple, gathered the future Knights of Ren and massacred the remaining students that night. It's implied the Kylo was already scheming something before Luke came into his bedroom. Luke just moved up the timetable.
I think since BEN'S Birth he has been groomed to become the next vador by a outside powerful force. ANd I believe that force fucked with Luke showing him shit that had not come to pass and used his fear of Ben becoming his father.
Which goes against what luke fought for in original trilogy.