Had high hopes at the start but they soon fell apart.
The story kind of a Harry Potter or MIB with dungeons and fantasy species. Thing is the Agency that regulates the magic on earth is rotten to the core, so far so good, greedy bastards wanting to maintain power and exclusivity of the system. Then werewolves, vampires, elves and fey appear and the thing is they (not all) are bloodthirsty monsters, they kill humans for sustenance or sport, but not one or two, on considerable numbers, still the people of the world is completely oblivious to this magical beings, even when dozens of people disappear every day (probably on the thousands worldwide)... in modern society, hard to believe.
Then you have the MC, he's a cautious guy, pretty intelligent, has agency, doesn't take shit from others and doesn't bow down to others trying to restrain his freedom. Pretty cool actually, unfortunately, for such a smart and cautious guy he makes blunders that are only explained as being forced by the author. And this plot tool is extended and used to force other scenarios, which leaves a bad taste and makes it annoying, it's a story that is consistent and logical, except when it doesn't want to be and the author needs to force the story.
Another drawback is that the author doesn't explain the world enough, so it's hard to tell when what happens if it makes sense, for example, at some point, an unrelated person in another world gets a whiff of mana, that leads within a minute to get the authorities conclude the MC is there... it seems ridiculous and the author doesn't explain crap, and this doesn't help.
It's a real pity, I'll keep reading some more, but I've lost the hope for this one. It could have been good but it's just mediocre.