How to deal with shrew

Can you hit him? If you can win, have a fight with him.

If he comes to haunt you in the future, as long as he is near you, you just have to tell him to "get out". Needless to say, he won't hit you if he can't beat you. As long as you don't pick on him, he won't pick on you again.

However, you should never expect such people to be honest. He won't bother you in front of you at most, but he will still speak ill of you behind your back. There's no way, unless you do worse than him and make him sick, he won't bother you again, but I think that's much harder than winning him.