The best aspect of the book is it’s deeply explored magic. The author explained what are the various types of wards, how can they be bypassed, weakness of common magic etc.
I'm rating it 3.5 stars primarily due to a personal preference: there's a 4-year-old child (both in age and height) who somehow goes around killing people who are centuries old which is not the book problem as the author or the mc stated multiple times that their age is working as a handicap, it’s more of a preference thing.
If you are looking for a plot hole or a more definitive flaw then I cannot give it to you? I enjoyed the book, read the first 2 books 4 days and am planning to read the third as well. It’s going to be published on 25th September.