I quite liked this and will read the next one about michael too. 

Sometimes I was a bit overwhelmed with the amount of angst and foreshadowing, so I didn't wanna continue, but I pulled through and enjoyed it. 

Dean is just the sweetest. And what the hell Simon.

Anyway, I thought the ending was a bit rushed, like

awful situation with simon having nyah and dean , then a demon is summoned, simon betrays demon, demon pulls him into the underworld or something and shwop - time jump and we're 2 weeks in the future and everyone is happy?

That situation just confused me a little at the end, didn't really explain very well, what actually happened and just ended so quickly.