I didn't want to be harsh on this, given the uniqueness of it's story. But I have to say even though it's tagged as Seinen it reads, flows and progresses like the most generic Shounen manga ever.
I believe Seinen has three key characteristics that must be maintained:
1)Very few internal monologues
2)Non linear story progression but no foreshadowing
3)Solution to problems that isn't fighting but by not showing the characters as smart and sometimes even unintentionally by casts whether by indirectly or mistakenly.
This Manga doesn't follow any of them. Characters are constantly monologue-ing. Story is just they are curing demons and beast while other people are creating problems from them with the general filler in between. Main antagonist is literally shown in that they are holding a meeting and their goals and agenda are shown as a segment. Most of the problems are solved with strength, power of friendship, or with this magical doraemon tool that makes the adventures dumb AF.
The premise of the story is very good but the execution and writing is subpar at best. There is no mystery because constant foreshadowing, there is no character building because everyone is constantly monologue-ing what they think and there is no tension because someone will come to save the day.
Somebody said this is better than dungeon meshi, bro how high are you?