Kubo is being Kubo:-
1. New villains appear, they seem to overpower good guy, then die the lamest deaths.
2.No backstory, no meaning to the new villains, they are just pawns without brains, hell in chess pawn development matters a lot but not in Kubo's story.
They are so forgettable, without meaning, a reader has no connection/ dare I say attachment to the characters.
3. There are no backgrounds in his drawings, he is clearly rushing it.
4. All of it feels like a slice fest, pop in a villian, pop in a good guy, spar, end battle, repeat.
5.He fails to invoke any kind of emotion in any fight, there is totally no meaning, as far as I am concerned, it wouldn't matter if all Sternritters are slayed in an instant. No depth to them whatsoever.
This arc started on a high note and now is a convoluted mess, best to collect chapters worth 2-3 months read them together.