Damn!! That's a great theory!! I was also thinking isn't He Tian uncle a shady/underworld type?? I think it was mentioned in the chapter when he made Red come to his place to cook for him. Anyway, I was thinking maybe he came across some info about what was about to go down but couldn't be the one to warn Jian Yi directly so tried to get Red to give him a warning in the form of the note... (which it looks like he forgot about) That's why he told Red not to look at it (so he don't get anymore involved). The main bad/superhot guy seems similar to He Tian to me.. What do you think? Am I stretching things too much?
I think he's trained. Remember the time Jian Yi wanted to skip school and go meet injured Xi when Red head smacked him with the stone? He was helping Jian Yi climb the school fence and the teacher caught them. He then climbed the fence with bare hands. The fence had sharp spikes. He was quite confident with that kind of movement. Normally, people won't try in case they fall onto the spikes. Jian Yi asked him if he's ever trained and he evaded the question. And not to mention he tamed red head with his glare alone before he had to beat him up. The delinquent got cold sweats and asked him who he is. And he live in an over-sized apartment with no decorations and is rich enough to offer red head a cooking job (he's just bullying red head so he won't pay but he hinted that he has the money.) And we don't see him doing any part time job. He's not your everyday high schooler.
It's just a coincidence that I was re-reading the entire series the other day. So when He Tian ran out to Jian Yi's house, I started thinking this way. I also always thought He Tian as a rich kid with family problem. Not someone shady. But he does have unusual interest in Jian Yi's issues. Maybe the other assumption about them being related might be right.
Why he tian knew that something was about to happen? (⊙…⊙ )