The worst mistery storys are those that dangle tons of character storys and world building in front of your face, give you a randomly breadcrumb if at all and when the time is coming for everything to be connected and revealed...it makes no sense whatsoever and is full of illogical things and plot holes.
I see that happening in this story very easily.
Out of all the mangas I have seen of this Mangaka...this is the worst executed one by far.
Trying to understand this is like trying to understand the mess of a power system of something like Jujutsi Kaisen...don´t even bother.
This seems like the Mangaka wanted to do this big detective story with tons of characters and plot threads...only to not know how to execute it properly.
This Mangaka is good at short stories which give you a little bit of explanation and still gives you a sense of wonder and mistery. But he went completly overboard with the lack of any explanation whatsoever...we are at Chapter 29....
There is mistery and then there is a list of random plot threads and characters which you just drop in to the story and then never develop.
I bet with everyone here that at something like chapter 150 we will still know absolutly nothing about any of the characters and the story and then it ends as an open ending.
I have seen to many storys with this kind of pattern and it is a damn shame.
Some might call me a pessemist, but I have seen zero evidence which shows that this is not the case.
I heavily recommend everyone to read his other works so you will get some value out of them...but I would not hold high expectations for this one sadly.