It didn‘t drop in quality, you just got used to the manga. The prequel was rather new and fresh (compared to most popular manga), and of course the characters were all new too. The author kept the quality in this sequel, but it‘s more of the same. And humans get used VERY fast to new things. Which makes some people think, the quality dipped, when in reality it‘s just that the „honeymoon“-phase faded.
In other words: if the stories of the prequel and sequel were swapped, you would probably say the exact thing.
I don't think there has been a big drop in quality, but something is definitely off. Compared to the prequel, the spin-off is much more action-oriented, which isn't bad per se, but story-telling wise, there's a noticeable dip. In the prequel, there were several organizations and groups that appeared naturally as the story went on, everyone had an objective and a bit of spotlight, sometimes colliding with each other. In turn, the sequel feels much more simple. A big group of assassins popped out of nowhere and all of a sudden it's an all-out war. The conflict has dragged for way too long and there's barely any dialog, which makes the story feels emptier.
I can't blame the author, but I would have liked a bit less action, focusing on the original characters and their lives after The Fable instead of a bunch of new characters that don't seem very interesting to me and that, honestly, don't add anything new to the story.
TL;DR. That's just my opinion. Thank you very much for this huge Christmas present.
You have done an amazingly good job as usual, and I hope you guys have a merry Christmas.
