Let me preface this review with this short note : A friend of mine recommended this anime to me, and as I discussed it with her, I realized that she had forgotten pretty much everything that happens after episode 5 outside of the broad lines of the story. That is basically what this review comes down to. After episode 5, the story (if you can even call it that) does nothing interesting.

So the show starts off pretty good. It has a really boring and generic Isekai setup about a guy who lived a boring forgettable life (so much so that that fact is never brought up in any relevant way really!), but after that point, it seems like a generic, slow, cozy (but good!) story about Will being brought up by 3 undead warriors from hundreds of years ago, which I think is a very cool premise. The characters were also honestly very interesting (Blood, Mary and Augustus are by far the 3 best characters of the entire show), it had a somewhat interesting world, with a cool history (though the author just won't stop bringing up the idea of telling us more about it just to have everyone shut up for a second and not do it), Mary's relationship to the gods is cool, the magic system is very cool with how words are just strong up together, a cool location for it all to take place in (the city of the dead and temple), it had fine voice acting and fine animation. It was looking to be an average anime with some plot holes (the actions of some of the characters early on make very little sense and cause problems that could very easily be solved by talking honestly for 5 minutes), some odd music choices, but it wasn't looking bad by any means.

Then... It happened. Oh god. Once you get to episode 5, things just start to happen constantly and I mean "things just start to happen constantly" literally. There's no downtime, no set up, no anything, [THING A] gets introduced and resolved by means of [SOLUTION A]. There is basically no overlap between story beats or world building to speak of. Thing gets introduced, thing gets explained (if needed), thing gets solved. This structure makes for a forgettable, uninteresting and extremely predictable story. The author apparently never heard of foreshadowing or buildups outside of a single joke about money being stronger than any magic.
This isn't helped by the fact that every character from this point onward has a severe case of "plot device syndrome", meaning that each and every one of them has only one purpose : to push the MC around. Characters have the depth of cardboard cutouts : Menel knows how things works, takes calculated actions but also cares for Will; Will is brain dead (allowing everyone to just tell him what to do without ever even considering the possibility of questioning any of it); the bard is a bard; the merchant does absolutely nothing of value; the prince doesn't have a personality, he just makes a death threat to the person who saved his city for having dared to ask for something after having told him that he was allowed to; the bishop is nice but acts as if he wants to be publicly hung for acting in the most despicable way possible; the list goes on. There are only 3 types of characters : the ones with 1 trait; the ones with 2 opposing traits (like Menel or the bishop); the ones that do incoherent things to create drama.
Oh also you remember a second ago when I wrote about how I find the setup of having Will be taught by 200 years old heroes interesting? Well that's never touched upon again, it's only brought up a few times as Will not wanting to talk about his past and of course Will is able to fit in perfectly with society outside of being strong, even with the 200 year old culture and knowledge gap (it's only really brought up a single time with the Bishop and never developed). So that's also ruined.
Honestly, that sums it up. It's a show with a good premise which is followed by high school levels of writing, there's no thought put into anything, things just simply happen one after the other.
There are a few good jokes like money being the strongest magic there is, but honestly, they are so few and far between it doesn't even come close to redeeming the show. Oh also gods function in absolutely incoherent ways, for instance the god of moving on with life allows people to keep living... more than once... then she keeps doing it... including with fucking undead people.

High 3. Nothing happens outside the designated 10 meter range around MC (oh also sometimes Will's main characteristic, being overwhelming strong, is just revoked sometimes cough cough episode 11 cough cough), the world has no thought put into it (if demons are such a serious threat, how is it that villages aren't fortified), characters are all either stupid or made to be hateable, the story doesn't commit to any single thing and just flip flops between ideas constantly. Watch something else, seriously.