Why is it always Gabriel?

One would think that dying was a final matter, a one-way ticket to wherever we go when we cease to exist. Apparently he was wrong. They had one last chance to make things right and Gabriel was going to do whatever it took for them to win. He couldn't wait to see his father's face when he realized what they would do to his precious story.

*Spoilers for the entire Supernatural show. I don't own the show or the characters, just the story.*
*English is not my first language.*
*Also, this is a Sabriel and a Destiel; the Destiel comes later.*
*The artist of the cover is monkeysiu on Tumblr*