The beginning is very hamfisted: the author spends perhaps a dozen paragraphs turning Harry into an entirely different person through Room of Requirement shenanigans. Even though there's justification for his changes, learning martial arts and weapon fighting and dangerous forbidden magic from a book, unsupervised, is never convincing. The story does get better once Harry gets to his special Mary Sue school that is of course better than Hogwarts in every way. There's adventure, decent OCs, lots of worldbuilding. It irked me that the author seems to have a boner for vampires and thinks it's perfectly fine to enslave people for thoughtcrime (simply *hating* vampires even without taking action against them) but it didn't stop me from reading it to the end, so I guess that counts for something.
If you've read fanfic over the past decade, a lot of this series will seem overdone and cliche. But it's good to remember that every cliche had something that *made* it cliche, and as far as I'm aware this was that fic - for bloodmagic, for major AUs, for there being a wider world out there, this was the beginning. Of course, I entered this fandom a good bit after this fic was new... But even then it was enjoyable. Still wish the series was completed though.
This fic, which is the first in an unfinished series, is a long and epic story arc that remains sadly incomplete. The fic itself may be annoying to some readers as it involves hyperbolic time chambers and a all powerful RoR, but this fic established an entirely new set of magics that changed how many people thought of HP fanfiction.