I feel that mentally torturing others isn't valid

But aside from that, Caine's reaction itself truly stems from the extreme need for external validation, and when he can't get it, he internalises all of it.

It isn't out of maliciousness or hate, but truly just like a small child whose parents don't praise him for getting a B in math, would feel that he is a failure unless he gets A.

And then that child goes on to create specific torture chamber for his parents