The first thing I'll get out of the way is that I feel The Zodiac Covenant doesn't fall under the criteria needed to be considered an isekai, so if you're here looking for a story where people get transported to another world and things take place there, this probably isn't your cup of tea. But if you enjoys series like "Why Does Nobody Remember Me in This World?", this might be something you enjoy. Though it's not much of an isekai, there is clear battle action and lore-building as well as memorable characters. Perhaps the only gaping flaw is that the scene transitions are not the greatest and can detract from the immersion quite a bit. The story also ends on a cliffhanger too, so fair warning in regards to that. Other than that, I think this is a solid story.