I very rarely rate things highly, but this is one of the cases where I felt this is justified.

It is 9/10 overall.

The work hasn't concluded yet, meaning there's still a small chance for them to screw it up and turn into something horrible, but chapters released so far were on masterpiece level.

Deep characters, great worldbuilding, tackling mortality, emotions, differences in lifespan and profound implication - all of this resulted in a work that is both gloomy, dark and at the same time awe-inspiring. It also contains one of the best takes on certain types of antagonists I ever encountered. There are also no usual cliches. No isekaied overpowered characters, no harems, no reincarnators, cheat powers, and other nonsense. The manga is taking itself seriously.

This is one of the rare cases where a manga fascinated me from the first chapters and kept delivering with every release.

I highly recommend it.