I can't bring myself to give a Harry Potter story a 1-star rating....but I'm not sure it deserves a 2-star rating. The first half was passable - reading as decent fanfiction, with a good bit of pandering, but not awful.
The second half (Part 2, specifically from the end of Part 2 Act III onward) was....awful. Abhorrent. It reminded me of particularly bad fanfiction. I was reminded, in one scene, of My Immortal. It made me so angry that the story was reduced to such a shredding of canon fact. I finished the book, but it was hard. And I am sad. And it is, for me, fanfiction. It will never be canon in my eyes.