Q's Relevance and Parallels to Double Black

I had a sudden brainwave of thoughts (read: I only got three hours of sleep last night) and needed to share. I've thought this for awhile but I really think Q will be returning to the series at some point.

First of all, there's just too much ambiguity there and I want to know more about Q in general. What happened to Q to spawn an ability like that? Why does Dazai speak about them like they're the devil incarnate? What was the incident that led to so many Mafia deaths in an effort to lock Q up? Is there any significance to Q's unusual eyes (remember that most characters tend to have fairly normal eyes, and this is a series where the eyes carry symbolic weight)? What's with Q being strung up in this position that is eerily similar to a crucifixion, shortly before Steinbeck has a conversation about God existing but not loving them?

There's a lot there. I've spoken about this before in the meta I did about Dazai's change in approach after the Q chapter, which was genuinely an unexpected event he did not anticipate. But there's something fascinating about the way Chuuya reacts to Q as well. In fact, both Dazai and Chuuya are almost uncharacteristically murderous towards this kid, and that's real interesting, seeing as many aspects of Q mirror aspects of their younger selves.