Out of all the shows in the winter (and now spring) anime seasons, this is the show I was the most conflicted on but for interesting reasons. Usually I feel conflicted on shows like Kill la Kill where I can say yes, I enjoyed it, but I do think that they did a lot of things very un-tastefully for thin reasons and, despite Maria's preference for psuedo-pleather-bondage-gear that wasn't my beef with it (given that similar clothes show up in the original manga-ka's other big work, Moyashimon, it must just be a think of his), heck I even found a lot of the sex jokes funny! My problem with it is slightly more complex, as mentioned above Maria lives in France during the 100 Years War so she has quite a bit of contact with the Catholic Church (both what I'm going to call "The Church of Heaven" to refer to her divine interactions and "The Church of the Earth" for those with the local priests) and, speaking as a former Catholic, and I just don't think that Masayuki Ishikawa knew as much about Catholicism as he thought he did!
While watching the show I never understood why Maria was being punished in the first place. She is both affected by the wars and Catholicism doesn't teach strict pacifism so that couldn't be the objection either. I finally found out the answer in a bit of an odd way but, apparently Catholicism considers sorcery and witchcraft to be bad and Maria was practicing her magic so publicly it was bound to be noticed (which matches up with why the other witches try to be more low-key with their spells). As a former Catholic that thought honestly never crossed my mind, there is a bit of Catholic mysticism and exorcisms always felt suspiciously like magic to me, and while I can't say for sure that the show didn't explicitly say this in an early episode I certainly missed whatever explanation it gave. But even that doesn't fully work, Catholicism is fine with miracles coming from God but not with powers from pagan sources but the series is surprisingly quiet on what the witches are, we see that Maria ages much more slowly than a human and that there are other "pagan" things in the world (although some, possibly all, were added in by the anime) but at least some of Maria's magic is fueled by her "faith" in herself so that's still a shaky justification to me. That's just looking at the story from a plot/motivation perspective, Bless from Mage in a Barrel had a great post on how the Church seems set up only to be shown in it's worst possible light and as if the people (who act upon beliefs) and the beliefs themselves are inseparable which is problematic to start with and downright dishonest considering how different the interpretations are today.
Moving back into the story, with an "antagonist" as flat and frustrating as we have here, the saving grace for the early episodes is Maria herself, although she's not super fleshed out at this point either. She's impulsive and determined, full of conviction and disdain which makes her feel fully like a teen who's growing closer to adulthood but not there yet and yet she's not an unlikable character. Her action in a world of passive persons (content to either pray or to continue fighting as they always have, not actively thinking about it) gives us a reason to connect to her and the fact that she wants to create a peaceful, war-free world is an understandable one to a modern day audience. The story does stumble later on when it has to go back and give her a reason to want these things (and still end with her having the same convictions) but by that later point the story has introduced enough other interesting characters that the story was keeping my attention despite the fumbles. I was actually surprised at how many of the characters ended up being sympathetic, Joseph (Maria's beau) I expected but even many of the witches like Viv ended up having understandable thoughts and beliefs that they were willing to put into action and it's the characters who did something who were the easiest to like.
I won't say that the antagonists were necessarily "interesting" but from a meta, outside of the story standpoint there's something surprising about the fact that both of Maria's human foes, the ones that she and the story interact with the most, are anime original characters. The manga (three volumes) was finished years before the anime aired but the monk Bernard and the mercenary Galfa (along with their respective associates) aren't from the manga at all and I'm curious how the manga handled Maria's interactions with both the church and the mercenaries without these central, representative characters to directly interact with. In some ways Maria herself interacts with them very little but Maria uses them to flesh out the conflicts much more fully and Galfa is integral to Joseph's own character growth. In the end Bernard does fall into the same church-strawman problem that Bless noted in his piece, especially in the final few episodes, but having him move "the Church of the Earth" around to oppose Maria was much more effective at creating stakes and trouble than just Archangel Michael's threat. And I do think that was the whole point for introducing these two characters, to create better "conflicts" in the story and just generally tighten up the pacing, this might be the rare case where the adaptation is stronger than the source material. I can say for sure that the art works better here as well, I was puzzled when I saw manga reviews complaining about how similar Maria, Artemis, and Priapus looked (even given that Maria's two familiars should look like her to a degree) until I actually saw the manga! They're welcome changes all around and help keep the story from dissolving in the later acts so kudos all around to the creative team.
Much like the earlier-mentioned Kill la Kill, I thought this story had a number of problems but I am ultimately recommending it to a specific kind of audience. If you want a historical fantasy with a more grounded setting than say Game of Thrones (in lieu of these recent remarks) and want a better take on idealism than Fate/Stay Night: Unlimited Blade Works has been doing recently then this is certainly something to check out. And even if you're on the fence I do recommend trying an episode or two, like I said Maria carries the show really well early on and the story has a lot of very nice character moments throughout. Funimation has licensed the show so it's streaming in their usual places and, if you're one of their special subscribers, you can hear the already completed "simuldub" as well (wish I had some thoughts on that but I can't even find a trailer for it on Funimation's site). Kodansha Comics USA is releasing the manga and has the first two volumes out and has plans to release the fourth volume which, as I understand it, isn't part of the main story and was released in Japan much later than the other three volumes. So, it's more or less a recommendation from me even if I'm not wholly sure if I'll buy it in the future myself (that really was a most infuriating strawman).