Well I don't think you should make him meet tang san at all. Maybe you could just make our MC challenge Shrek and defeat all those guys. It's enough for me. I don't even care tang san is alive or not. I just don't want tang san anywhere near interfering in our MC's life.If he does,thrash him for good.You could just go in your original direction without meeting that plot armor shit. Also could you make him the reincarnation of a god or something, and make the other gods his past friends or something and they are helping him reach his past gloryness or something. It's just our MC depending on unknown gods leaves a bad taste in my mouth. Good luck!!!!
Okay, didn't you say you weren't going to make him crazy loud? , have him change school is better since that is how he goes with tang san his techniques will work for him both the movement and the demonic eyes although you can add more since those techniques are the ones that tang san prefers you can add more to his repertoire like the spear attempt