He's a quiet sociopath who wanted to change despite his condition. It all started when he was 10 years old when they moved to a new home, he was forbidden him to go outside due to the high risk of daytime kidnappers and such. He doesn't know any friends on the new lot and most of the kids there are very mean. So he's only alone in his room, playing video games and stuff. He rarely fantasizes having good real friends and having adventures in his room, he rarely cries a little too when fantasizing. What's worse is that his parents mostly misunderstood him when he was in his room. His parents would mostly assume he was masturbating, but it will just cause great disappointment to Mark.
He became a sociopath at age 13 because of lack of friends over 3 years. Then his parents doesn't care about his sociopath behaviour, as they always neglect is and assume that his behavior is just like other normal kids does.
At the age of 15, he ran away from his parents at midnight and goes back to his old hometown where most of his good friends live there. But unfortunately, most of his friends aren't there anymore, therefore it just brought Mark with great utter disappointment and depression.
He sat on a bench after and tries to fantasize the same thing he wanted, then a person came to Mark. It was a female, she recognized Mark because she has friends that are friends with Mark before. She let Mark to invite him on her house so they can talk about what happened. Mark told all the truth, the female friend then understands what happened and suggested he should be checked up, but Mark denied the suggestion because he know his sociopathic self cannot be cured. So she let Mark stay in her house and treat him like a family member (or a brother perhaps).
After a long week, Mark had some drastic changes in his behavior despite he's a sociopath and he made friends again. Then one day, his friend revealed she has telekinetic powers and she's been practicing to balance it off for many years. She gave Mark half of her powers and taught him how to use it.
Then one day, his friend was dying because of accidental misusing of her powers. She told Mark that he shouldn't let the same thing happened to herself before she died. Her death was mourned by many people, especially Mark. Mark promised to revive her soon, a new quest for him.