Son-In-Law Who Protects the Country

One general's achievements lead to thousands of bones being withered. He is the chosen god of war, but he hides in a lonely family and becomes a son-in-law. He was once a powerful person all over the world, but now he is hiding his name, and he is doing it for a girl. Is it really a hero who has a hard time with a beauty? Is the hero too late to be bloody? Big mistake! Everything he did was to save the country from danger!