Aggressively average. Trite, even.
Our unlikely heroine is lazy, weak and apparently not the sharpest tool in the drawer. We're off to an original start. W00t. Other very interesting characters include the saccharine guardian, the all-powerful yet occasionally goofy grand master, the cute talking animal that only the heroine can understand, the 'unique because weird' girl, the ambiguously mean school girl clique, the stern tsundere, the mean tsundere, and the tragic tsundere.
I'll give the implausible setting and circumstances of the story a pass on the grounds that this is fantasy... Well, most of a pass, anyways. I have questions. Questions like "if you yourselves are the targets of these otherworldly flint knappers then why do you routinely split up into vulnerable two-member patrols to seek them out," or "why are you, who habitually scoffs at our heroine, so incredulously outraged when she fails to accomplish what more experienced and competent warriors could not?" And also, what the hell is "Bort" supposed to be—some sort of weird misapprehension of Q-carbon, only "Q-car" is a sort of $%^& name?*
It's not bad, but it's not good. It's very, very... okay.
*: Yes, I did in fact look this up. No, I didn't find anything. No, I don't know why I didn't find anything. Regardless, "bort" is apparently a low grade diamond used for abrasives, and not in fact some sort of superior form as the show seems to imply. Thanks for your concern, and you have a great day now.