Volume 10 was so-so. I was not a fan of the coin hunting arc, but the adventure with Agent Rabbit was fun, because I like Rabbit. Of course it was great to see Shigure again.
The mini arc with Samael was dark, but interesting. I like it when Eight gets exposed to different views that show him how not everything is simple black and white.
The next arc is going to be about Lady, which means we'll probably get nothing but fanservice galore.
You're right, the plot isn't progressing at all.There are Asuya and the cat girl on the other side, which will probably face Eight at some point, but other than that he stands no chance against the organization.
It'll probably end like Kenichi and Tokiwa where the "masters" will join the final battle and fight the really strong enemies while the students do their thing.
Talking about a possible ending: If sales continue to drop it might not be too far off.
In week 2 volume 10 ranked at 276 and sold around 4k copies. That makes around 17.8k total. It's unlikely that it'll make it into the next weekly ranking, because it dropped out of the daily top 500 after 14 days.