It was probably one of my favorite so far, with volume 3 (I think). I really like that Subaru is finally doing things. I say finally, but obviously he was instrumental in volume 3 as well. Basically, he is a specialized anti-magic beast and anti-cultist unit 
spend one black, return Subaru from cemetery to the field. Add a witch smell marker on Subaru.
It felt nice that he was basically considered the MVP this time. I hope to see more things like that in the future. Also he learned to ride! He is getting more independent!
I’m not super sure about the part on Wilhelm. I feel like it left out a lot, while still spending a lot of time just in the middle of plot. Like, what kind of crazy training did Wilhelm undertake to be able to overcome the 剣聖? Is he the father of the current 剣聖? Plus all the other stuff I commented previously about. But since he is tagging along, we will probably get to talk to him a bit more once we are done with the current troubles. (Speaking of which, too bad Subaru cannot have a voluntary savepoint… Man, that must make the next fight even more nerve-wracking for him… even though for me it feels like this loop is “too big to fail”, so I expect positive results.
I really liked Julius in this book too.
I wanted to write more, but I never have the time, and it’s been days already since I finished the book. So, I’m just going to post this and be done with it. Better than no post