Questions and commentary about chapters 166 and 167

In 166, when Akabane confesses his murder, there's a scene when he say "he was connected to forces that bring evil in society" or something... What is that thing depicted in the panel? I'm thinking it should be something hinting at what those "forces" are, but I don't get it

Am I just overthinking it and it's a cutaway to the apartment complex wall or something?

Regarding this flashback, I can say I like the direction it went for - I certainly did not expect Kiritani to die, my guess from the spoilers was that he used cloning to divide his split personalities, but the result is the same

Asshole could have not done it in front of his cloned children, lol

I don't really get how he went from a mediocre writer to someone able to build a magic cloning machine in a basement, but I also guessed that the cloning technology would come from the divine dragons too; also it's a bit absurd how he was able to reveal Akabane's murder by finding a single strand of blond hair, guess he's also a master detective

All in all, very interesting flashback, I think after such reveals that pretty much lay out the whole background and explain away all the mysteries, we'll be heading toward the serie finale