Okie dokie! Imma just come out and say I don't think He Tian fighting She Li is the right way to go
We all (to varying degrees) want to see She Li pay. I could do a whole compare/contrast on HT/SheLi dynamics; what makes them the same and different yadda yadda
BUT
Here's the thing: Having He Tian react to what She Li did completely defeats the purpose of Mo Guan Shan's character arc
There is a lot of emotions out here in this space that treat Mo like the "Damsel in Distress" trope. The thing is Mo has never been helpless; that is what his whole journey has been about (well, among other, incredibly gay things)
Firstly I think Mo is a character a lot of people identify with because 1) this is the character we have the most active knowledge about and 2) a LOT of his experiences mirror the average human being's (feeling wrong, being unable to match expectations, being insecure, doing good things and being punished for exposing that vulnerability, etc.)
Obviously his life is much more dramatic but the core essence is the same- he is a sensitive, naive person growing up in a harsh and unforgiving world. Mo is taken advantage of and is coloured as a burden on society (and who hasn't felt out of place in their world at one time or another)
Second(ly?) Mo is not helpless. His entire relationship with He Tian has been MGS pointedly NOT backing down to HT's demands (again, another post). Through these actions (and the unrelenting affection of the all the boys; "we miss you when you aren't around" vibe) Mo gained the strength to see a world beyond what he thought was possible for himself AND what he was capable of. Confronting She Li put all that into action
Third(ly??) This is STILL Mo's character arc, which means it should be Mo's decision on how to handle She Li. Not He Tian's. Mo is a bleeding heart- he yells and hits because if he looks too long in your eyes he'll see your sadness and, like a orphaned baby, he'll pick you up and take you home (cussing you out all the while). Moreso MGS isn't a revenge character, he doesn't look to who has wronged him and figure out ways to make the person hurt. That's why he's got friends like Buzzcut (he sees a person hurting and takes that burden for them.)
All this to say: Mo doesn't care about She Li(anymore), he focuses on the people in his life who matter. If She Li "accidently" got tossed into a garbage truck, well that's fine but it isn't the aim. Mo is FINALLY thinking about himself and a future that he actually looks forward too- and he came to that conclusion by himself (with the latest chapter369)
He Tian going to 'get revenge' on She Li not only continues the cycle of violence Mo has had to endure, but will only ignite further abuse to all sides of this issue. It Is Not Worth It
If you read this far, you are an impeccable human being, I didn't mean to drag this on for so long- hope you have a good day!