The Ashen Witch, Elaina, is travelling the world. That's not true in ep.1, since she only graduates at the end of it, but after that she's just a flying tourist. She visits a new country in every episode. The show's effectively an anthology, albeit with some recurring characters who appear in multiple episodes.
The stories are okay. They can be amusing, horrific or just sort of watchable. Ep.9 is flamboyantly nasty and comes with a content advisory warning at the beginning. "This episode contains explicit content that may be inappropriate for younger viewers." (It's not that bad, actually, but it's definitely diving head first into darkness.) Ep.4 is arguably more horrible, actually. (XXX was a bastard, so YYY committed genocide and went mad. The killing is gruesome and drawn-out too.)
The show's problem is Elaina. Firstly, she's a bystander who's reluctant to lift a finger to help and can appear callous. She's not actually a bad person, but both segments of ep.3 make her look uninterested in other people's lives and deaths. She kills people, does nothing and calmly flies away. (She hadn't meant to kill them, but she did.) She changes nothing in those segments, leaving the situation unchanged from how it had been before she arrived. If things look dangerous, the only person she'll try to protect is herself. Also, she's got a big ego. Her childish competitiveness at the start of ep.9 (with a client!) can piss off and die. She regularly calls herself beautiful. Cut her hair a bit shorter and she'll demand the death penalty, even though she can restore her hair easily with a spell. (To be precise, we see her reattach the cut hairs, which I'd have thought was much more difficult to me than just fast-growing more of it. As early as ep.2, incidentally, we'd seen her using time-reversal magic to reverse damage.)
If you ask for assistance, though, she'll say things like, "Will I gain anything by helping you?"
She's not malicious or nasty. She doesn't mean any harm. She does a bit of good, here and there... but she's cold and she's a bystander protagonist who prefers to watch events unfolding without her. An actual bastard would have been more entertaining.
She's likeable in ep.1, in which her magic teacher puts her through hell. Elaina is actually being a proper protagonist in that episode and it makes her engaging and sympathetic. I was okay with her for the first half of the series, but then I hit ep.8 and her demand that someone be executed for cutting hair. After that, I'd lost patience. I was delighted when ep.10 was a flashback episode with the previous generation of witches (i.e. no Elaina)... only to find that its replacement protagonists were even worse and I hated them like poison. Sheila and Fran are punchable and even Nike is annoying with her repeated demands about money when a client's trying to say what he wants them to do. The end of the episode is meant to redeem Sheila and Fran. In practice, for me, it didn't. They're cool against bad guys, yes, but they're still idiots and I still wanted to see them drowned.
There are also episodes I disliked for non-Elaina reasons. Ep.6 is about a country where the king has cast a magic spell that makes it impossible to lie. The story's opinion about this is very Japanese. It's meant to be a funny episode, but personally I cried bullshit. The overreactions are silly and it's absurd to imply that society would be paralysed like that. Yes, it would make trade more complicated, for instance, but people would still do it. Life would go on.
Then, after that, ep.7 has a country that's split itself in two with a wall because its two halves don't like each other. It's a story of idiots. I didn't care and everything that happens is far too predictable.
This isn't a terrible show at all. It's quite well made and there are plenty of people who like Elaina. Good luck to them. If you're okay with its "heroine", you'll probably think the show's good. Personally, I liked Saya and I thought the show had some strong episodes, but quite a lot of it made me want to fast-forward.