Backstory
He was originally a young 13-year-old living a normal life, but when he moved to his new town with his beloved younger brother and parents, he began to change during the first day as a sudden pain came upon him. The next day Jeff got the feeling again and brutally beat up a trio bullies, a year younger then him, named Randy, Keith & Troy, who were picking on him and his brother Liu by telling them that every kid in the neighborhood has to play along on handing over money.
The next day Jeff was visited by some officers who had been reported witnesses of a kid beating up three others, Jeff knew the police suspected his brother for it and confessed the truth, they then tell him that he will be sent to a correctional facility for a year, but just after that Liu popped out and straight away took the blame for what had happened to repay his brother for protecting him and was arrested, sending Jeff into a depression that seemed forever.
After at least a few days, Jeff went to a birthday party where him and his family were invited to on the day they first moved in. Jeff seemed a bit happy for a bit until, the same bullies located him to get revenge, Jeff tried to reason with Randy telling him that he had beaten him up and he has to suffer depression and guilt, Randy however wasn't very reasonable and decided to go for winning as he brutally beat up Jeff as Keith and Troy held the kids and parents at gunpoint to prevent them from interrupting the fight, Randy taunted Jeff's brother during the fight and it caused Jeff to get the feeling again and the feeling snapped his mind making it permanent, which had caused him to kill Randy. He then managed to beat down Troy, but not before he could finish off Keith as he set him on fire from some bleach that got on the two and some vodka that Randy smashed over his head during the fight.
Jeff woke up in a hospital, his head was wrapped in bandages. When the bandages were taken off, it was revealed that his face had become grotesquely deformed and extremely pale from the burns, with bright red lips and a leathery texture. Jeff said that he liked his face this way and laughed hysterically, but the doctor foolishly thought that this insanity was just the result of the painkillers and let Jeff and his family (including Liu, who was released) go home.
Later that night, Jeff's mother woke up to find him in the bathroom carving a permanent smile up to his cheeks from his mouth so that he would no longer have to exert energy to smile, as he put it, and burned off his eyelids so that he could always see his "beautiful" face and wouldn't have to blink anymore. Jeff's mother went to her husband to tell him that their son had gone completely mad and needed to be killed, but Jeff caught his mother before she could say anything else. So Jeff ran toward his parents and gutted them. This woke up Liu, as Jeff suddenly walked into his room and "killed" him, with Jeff telling him as he was about to plunge the knife into his heart, "just go to sleep".