Some of the things that made Bleach a great series for a short while was it's premise, world-building, and cast of characters. With the exception of the two protagonists that so far work really well together, this story has very little to support what they contribute to the whole of the series. And while Kubo is always going to have a knack for strong characterizations, there is too big of a flaw here with it's premise for an epic battle scene between witches and dragons to overcome. Let's begin with it's setting "Reverse London" (not entirely sure what it means still) the biggest symbol that serves as foundation for the construction of it's antagonists is the London coat of arms which consists of dragons. (Or, maybe ahem, flag of Gryffindor) It's such a hokey plot device compared to something mysterious like the Hogyoku which added an extra layer to the overarching story when Aizen uses it to create Arrancar

There is a very strange mix of modern technology introduced here as well that doesn't seem to fit at all with the tone of the series where we are given little to no backstory on Ninny.

It seems to only serve as a distraction for the more interesting questions about the enchanting and otherworldly aspects. The "Soul Society" in Bleach is a beautiful departure from the stereotypical Death God setting whereas "Reverse London" is, I guess, sort of like London, but not really.