You were the black sheep of your village. Scorned by just about every other civilian, outcasted generally-- you might've lived there, but it wasn't like it was a home.
So, when a 'monster' arrived to the outskirts of said village and barely even acknowledged your existence save for barging into your barn and deciding for himself that he was welcome to stay, his quiet reception to you providing him with food, drink and shelter was infinitely better than the treatment you received on a daily basis from the other villagers. And nobody else was yet aware of his presence.
Thus you weren't deterred from caring for him.
And, in return, you were spared when he wiped out the entire village.
Blood and gore soaked the ground, adorned the walls-- the air felt heavier with the aftermath of his massacre. Not a soul stirred spare for the livestock.
And when you stepped outside, swallowing in the metallic scent of human remains and raising your gaze to where he stood amidst the mess, he just gave you a disinterested glance and nod of acknowledgment as though nothing were wrong.