As far as books inspired by video games go, this is better than I expected (with the admission that I set the bar quite low for anything inspired by video games). This one technically enscribes itself as a prequel to the state of the world in League of Legends as the fight against ruination was an event of the game whose resolution was very disappointing. This somewhat impacts my appreciation of this book as despite some of its qualities and the straightforward fun aspect of seeing characters exist outside of the limited realm of the game, the nagging feeling of "I know how this all ends and it's bad" never left the back of my mind. Additionally the book's writing does suffer from teenager-like writing often found associated with video game related media. The world being a dark medieval fantasy story of 

a man's slow descent into madness ending with the slaughter of an entire nation

it clashes with the characters' often too laid back attitude and "youthanised" talk. Overall the core idea of the story is good and I would go as far as saying the execution is mostly well done (there is the occasional bit of awkward railroading into making things happen so that they're just like in the game) but it's just lacking a bit of polish to really make it stand out for people who won't (like me) have a positively biased rating due to their love of the source game.