Unfortunately ML will not change his behavior. He will "love" the MC. He will become obsessive to the point of hurting the MC over and over again.
And the MC being the ever so kind and in love he is, took it all and blames himself all the time
Anyway you can read the novel for more context but be prepared to shed tears almost every chapter.
There were few chapters with sweet moments. I can't describe it as him treating Inseob kindly though. ML is not sane.
I personally just feel sad reading this novel.
That feeling when you can't be happy for the characters because you know that shit will go down few chapters ahead because ML is so predictably unpredictable. Sorry, I'm not good at explaining.
Anyway, I still highly recommend you read through some chapters so that you can get the idea.
Can someone pls give me spoilers if ml will change. And how