I don't write reviews often, almost never actually, but when I do it's because of something a bit more extreme then usual. Usually because it's terribly bad in some way.
This review isn't just about one book in the series, it's about all seven of them. The books themselves are terribly short at around 200-250 pages, the last one going under 200.
Let me start by saying that if you cannot read around sexism, misogyny, racism, Russian nationalism, homophobia/hate, etc. This entire series is not for you the first (free) book isn't that bad, the farther you go into the series, the worse it becomes and you'll be able to ignore it less and less. If you love that sort of thing, this series will rate an absolute 5 out of 5 for you, you won't notice the other things wrong in the books, I just don't want to know you. If you can read around those things, I still am not certain that you should read this series.
One really annoying thing in the series is inconsistency, some of it you could write of due to a bad translation (from Russian), but it's so rampant that I suspect that it's the author and no one did any actual good editing. The author is also very bad at math and numbers in general, the average of a price of 10.000 and 100.000 isn't 50.000, it's 55.000. That's the most obvious example, but there are many, many others. On their own not an issue, but combined with the inconsistencies, it's starts to annoy.
The first book is free, it's the least offensive in the lineup, but the rest of the series isn't worth $5-$7 for a digital copy that's so short and certainly not the $17 for a physical copy.
Not everything is bad though, I read through the series in a week and quite often the writer had my attention with cool ideas that made me want to see what happened next. But then absolutely grinding to a halt when he went of again about the "place of the woman and the role of the man" or a "girlfriends training manual". Being an Goblin, Orc, or Troll is alright, even an actual demon is (initially) welcomed as an ally, but if you black, yellow or god forbid, Jewish... *facepalm* This isn't unique to this series or this character by this author, I checked out his other book and found similar issues. It's as if it was written with a certain target audience in mind...
This could have been an interesting and enjoyable experience if all the bigotry was removed and a good editor went over the book with a fine tooth-comb removing all the inconsistencies.
I'm no white knight, I can read/watch around a lot of stuff that I don't agree with or have no interest in. But even I have limits and this sorely tested them. There is bigotry in a lot of older titles, written in a different time, for example The Destroyer series which was mostly written in the 60s-70s, but this is from a (Russian) kid and written in 2012-2015.
There are far better, more consistent, and less offensive titles that cover this genre.