It's sort of okay. I wouldn't recommend it and I never felt the urge to watch more than one episode at once, but I didn't hate it or anything. It's about armoured men with swords who have a duty to kill demons.
Garo was originally a 2005 live-action tokusatsu franchise, but not for children. The characterisation was dark, the demons were liable to be sexualised and it was broadcast in an adult timeslot. It's still tokusatsu, though. It's still based around fight scenes between stunt men in goofy costumes, which these days will be CGI-enhanced too.
This was successful enough to spawn a franchise which, this being Japan, includes anime. This is the second such series, after Garo: The Carved Seal of Flames (2014). I'd watched that, so I watched this too. They're not related, though. There's no cast overlap and they're set on different continents in different centuries. Instead, what they both have that the live-action versions don't, is a historical setting. Going back in time on TV is expensive. Reality is cheap. That doesn't matter for anime, though. The 2014 series was doing what looked like Spain under the Inquisition. Meanwhile this series is returning to the 10th century with historical figures like Abe no Seimei, Minamoto no Yorimitsu/Raikou, Sakata Kintoki (the basis for the folk hero Kintaro), Ashiya Douman, etc. (They're liable to be descendants of the originals, though, and in the case of Seimei gender-flipped.)
Problems with this show:
1. All the men are boring... no, that's unfair. I'll rephrase that. None of them are interesting. They're intense and they fight demons and/or wrestle with their social consciences. They're admirably loyal and serious-minded, but they're doing that samurai thing of suppressing anything that could be mistaken for a personality. None of them have a sense of humour. I didn't feel that the voice actors were really adding much either, generally going for the expected macho, slightly overblown reading.
At least the 2014 series had loud, outrageous protagonists in Luis and Leon. Here Raikou is bland, Kintoki is pointless and Yasusuke is unlikeable. It's paradoxically interesting, in a forensic sort of way, to study the hollowness of Raikou's heroism at the finale. Oh, we believe that he's a good, noble, pure person. We just don't care. Even after being the hero of all those episodes, he still hasn't come alive as a dramatic character.
2. The show looks cheaper. Apparently the 2014 series sold badly on DVD, so the animation quality appears to have been downgraded. Personally I don't really care about that, though.
3. The story arc is fairly dull and there aren't many strong episodes. Ep.5 is a standout, but after that I'm struggling. Seimei's story is the only thing that really springs to mind as a story arc at all and that's hardly enough to carry 24 episodes, even if Seimei is the show's one decent character. The villains are oddly passive, while I really, really don't care about anything Yasusuke-related after his introduction. Even if I liked that trope in general (which I don't), they're not really exploring it or taking it anywhere.
Seimei (played by Romi Park) is at least memorable, though. It would be a stretch to call her likeable, admittedly. I get the impression that this franchise doesn't really go for "likeable". She's a lying, thieving, selfish, gluttonous tease. However there's a lot under that surface, if you're willing to stick around for it, and she's a central female character and hence immune to the Boring Samurai Problem. When she's around, the show feels as if it has a focus.
Ep.12 was fascinating, though. It's like a recap filler episode, but different. Traditionally such things have always been clip compilations from earlier episodes, cobbled together when a production team can't meet their deadlines. I'm sure the motivation here was the same, but this one's effectively a DVD extra. It's filmed in live-action. The four main voice actors have dinner together. They talk shop, discussing the problems they've had with their roles. They tease each other. They watch clips from the show and make remarkably few comments, but things perk up when they start choosing their favourite bits and explaining their reasons. It's really interesting! I don't know if I'd be saying the same if I watched more DVD extras, but it's quite cool to see these people in the flesh and to hear their point of view.
It all feels natural and unscripted, which is as it should be. (I'm surprised the producers didn't request another take of the actors finding more to say in the commentary sections, for instance.)
The historical angle is mildly interesting. We see kemari in ep.11 and of course we have the famous Heian hats.
I've been pretty negative about this show, but I wasn't struggling to get through it. I watched an episode a day. I was never tempted to watch two back-to-back, but it's manageable in one-off instalments. The only episode I actively disliked was ep.16, with the comedy sexual harassment. Seimei's lively. Theoretically I quite like the show's pseudo-horror formula (with demons actually called Horrors), with its built-in assumption of tragedy, wanton cruelty and the innocent being devoured. There's lots of potential in that, which is sometimes even realised. We'll see plague, meaningless death and loved ones coughing up blood. That's a plus, at least.
In practice, though, it would be slightly kind to this show even to call it bog-standard. I wasn't a massive fan of the 2014 series, but it had more life than this.