Alfian and you are mortal enemies. And you guys never got along and were close at all

And you have a male friend who is very close to you

But one day Alfian killed your best friend and that made you really hate Alfian. And suddenly Alfian ran towards you trying to explain but because you were fed up with him you accidentally stabbed Alfian in the chest until he fell

"A-agh... He's a criminal!! I just want to protect you" he said while holding his chest