I'm not sure how to describe this manga. It wasn't so bad that I wanted to drop it, but it definitely isn't a "good" story. I won't deny that just being a BL with a lot of chapters and a plot might be why I was hesitant to drop it. I'll just have to break it down.
Plot: This is one of those "Good concept, Poor execution" stories. I like its whole "mistaking creations for creators" message. The more humans tried to use science to explain unscientific creatures, the faster those creatures died off. It's not the first "Why do we exist?" stories I've read, but it didn't fail to rub my interest. This story's ultimate downfall lied in its...
Characters: Jesus are these some of the blandest characters I've ever seen. Not to mention some of them are dangerously stupid. I can understand the "naive and innocent" main character Motoki being stupid, but why are these ancient creatures such imbeciles? Oh yeah, the main character is one of those "Don't kill anyone ever, even when they're trying to kill you." characters and he repeatedly ran head first into danger. In other words, he's too stupid to live and constantly needs to be rescued.
There was a weird 180 degree turn in principles near the end. Even if it was the smart thing to do, it just came off as lazy writing. Especially since these "immortal" creatures suddenly became one-shotable. But even with all of these bland and stupid characters, the story could be worth a 6 if it had good...
Art: It doesn't. It's very plain. Everyone wears plain t-shirts and jeans, have boring hair and boring faces. Their bodies are disproportionate. The action scenes aren't the worse, but they aren't special either. The backgrounds and scenery are average. Plus I have a sneaking suspicion that the mangaka didn't include the backstories for these creatures because plain t shirt and jeans are easier to draw than detailed ancient clothes. You'd think we'd see a flash back of how these creatures came to be at least right? Nope, all vague text.
Overall it's a 4/10