To be honest, I would separate TPN into two sections. The first 3 or so arcs (first 99 chapters I believe) is a solid 8.5/10 for me. The world-building is top notch, characterization is great, and the series has a wealth of complex relationship building while crafting great strategies and mysteries.

After that though, the story takes a pretty big nosedive, almost immediately. I fail to see how the series now is anything higher than a 5/10 at most. It feels like the authors want to rush everything and have just invalidated all the careful planning those first 99 chapters seemed to set up. Characters are simply caricatures of what they once were, none of the antagonists are as good as those in the first 3 arcs, and the world-building is laughably nonexistent, and the conflicts reduced to simple 'good vs bad'.

Anyway if you came here for ratings, here are mine separated for TPN's first 'half' and second 'half':

Story (first half): 9/10
Story (second half): 5/10

Art (first half): 8/10
Art (second half): 7/10

Character (first half): 8/10
Character (second half): 3/10

Enjoyment (first half): 9/10
Enjoyment (second half): 4/10

Overall (first half): 8.5/10
Overall (second half): 4/10