I didn't notice the tags... ( ´ ▽ `; )ゝ
And I must say, that human was pretty selfish. But that's how humans are after all...
Also, I do think the manga was beautiful, I liked the art, the atmosphere and the story.
That angel was so carefree which fits well the character because she has wings and wings are a sign of freedom and lightness. She kinda complete her lover, I guess
I think the end means that the person you love the most deserve a second chance, even if they did bad things to you, they probably did it because they were scared and don't want to break the bond. There's always a reason behind acts. At least, it was a great end!