Tengoku Daimakyou's story layering is very underrated. They throw clues at you at early chapters which naturally you'd ignore, only to go back to these early chapters after you read a bit further and realise what they were implying back then. The re-readability of this manga is insane. The mystery aspect and the characterization is fantastic, however it doesn't just spoon-feed you the plot, you need to as i said before, use your head a bit. I really enjoy both the world and the dynamic between the main 2 protagonists, getting very big Akira(manga) vibes. The art is very nice, the backgrounds and the worlds especially arevery well drawn and really drive into you the "dystopian/overgrown/abandoned" civilisation aspect.
Definitely recommended!