I do like this novel. There are some aspects of it that I personally dislike, but I think other people would like.
It's a crossover work that includes AU elements for that to work, and I think the blending of the worlds is pretty well done, definitely from a power system view.
The part I dislike personally is that for at least for the first 30 chapters or so, it's more of an OC story than AU if you get what I mean.
Most fanfiction are very canon compliant, which is something I don't like. Then, there are about 3 different levels of AU fics.
Level 1 is labelled as AU but is really still a canon retelling with a new character involved.
Level 2 is still based on canon events initially but eventually goes into another direction based on the accumulation of small changes.
Level 3 has 2 different routes, where either they have the characters in a different setting or setting itself has a lot of massive differences.
An OC story, in my view, is essentially a story that's not really relevant to any of the source material's plot, and that can fit any of those categories.
And that's where I fell this story land mostly so far and that's fine within itself but I felt from both the synopsis and the first chapter the aim for the story was the crossover not random unnecessary drama. Like again, I'm not saying it wasn't well written, but that is not the perception that this novel gave as to what it was going to be.
That's changed after around chapter 30, which I do like, but it then makes all those previous chapters essentially a very long prologue. Like everything up till he gets to Japan.
The structure of the novel is weird because of that. If you were writing a completely new story, just using the setting or because of the crossover, multiple settings, that would be fine, but then why are you now interfering with the plot.
And if the wasn't the intention, then you essentially have unnecessarily long prologue that could have easily been cut down by half if not more.
With that being said, it's not like it was uninteresting, it definitely was, and the writing quality is very high quality, and besides the Lord of Mysteries aspect not being that well explained in comparison, the actual crossover worlds have been pretty well explained in how everything fits in together.
I'm definitely going to keep on reading, and I recommend it to anyone who sees this to give it a go.