Star Wars - The Force Awakens Kylo Ren is Han and Leia's son. His real name is Ben Solo. He was trained by Luke but then turned to the Dark Side which was the reason for Luke blaming himself & disappearing.
I love this scene so much, you can see it in his stance, he's uncertain, off-balanced, and he's not as strong and determined as he used to be. Rey has broken down his walls and no matter how hard he tries he can't build them back up.