The Ancient Magus' Bride belongs to the shonen audience category, despite the fact that some people might not be aware of this. Some find it surprising that this is not an action series but rather a grim supernatural fantasy with hints of romance. The end result is an anime series with a distinctively magical universe, yet one that it doesn't adequately define.
When compared to other fantasy novels, The Ancient Magus' Bride gives its setting far less explanation and world-building. This is made worse by how frequently the series switches its subject, making its tempo difficult to follow. The final show, which mostly relies on the caliber of the manga source material that it has been stretching out thus far, sometimes feels disjointed and occasionally almost excruciatingly sluggish.
The Ancient Magus' Bride Has Slow Pacing Issues
The biggest reason why things feel so disjoined in The Ancient Magus' Bride is the fact that the pacing is so sluggish. For one, the show takes chapters from the manga and artificially extends them with additional scenes and content. This turns a slow-paced fantasy slice-of-life series into a much more plodding story than it should be. Throughout these sequences, very little of the magical world that Chise finds herself a part of is explained. Thus, there's not much consistency in the numerous settings or the mystical, magical elements that appear in them.
Ironically, the first season's final episodes feel hurried, as if they were trying to catch up with all the content they had been putting off by taking their time. Once more, this results in a situation where important details, such as how things truly function in this universe, are generally overlooked and notions are applied hastily in order to forward the plot. It's obvious that some of the supporting characters are merely there to set up forthcoming events because they aren't given the attention they require to have an impact. In other words, the only things that the world is built for in the first season are frequently unimportant. Thankfully, the development has largely "fixed" these pacing issues.
Ancient Magus' Bride's Worst Narrative Choice Fits the Heroine's Mentality
The Ancient Magus' Bride often jumps around and shifts its point of view between Chise and Elias. On the surface, this only adds to its disjoined narrative and pacing issues. On the other hand, it somewhat justifies them in the fact that so much is still based around Chise. The vibe throughout the series is neither too magical nor too gloomy, but it does have the effect of emulating the changes in Chise's depression and self-destructive actions. This might contribute to the speed changing a little as Chise develops as a character and works to overcome her preexisting limitations. Similar to Elias, who isn't even human and has trouble understanding the notion of emotions, the remaining episodes of the series concentrate on how he gets to know his titular new bride. For all intents and purposes, that is also how things are for the primary characters, so things feel unusual and out of the ordinary.
This is also why the settings are so surreal, with the anime's version of England seeming particularly idealized. This gives the series a sort of dreamlike nature, creating a sense that the world-building is more about the sensations that the story brings about than its concrete elements. If anything, the world is more a collection of loose facts and memories of sorts, which is why it pulls from so many disparate magic systems and mythologies. It doesn't make for perfect television programming, but it does create a unique experience that's turned The Ancient Magus' Bride into a fan favorite for many anime viewers.