Source of Arsha's power

"Since you did so poorly against purely physical attack, I wonder how will you fare against a magical one?" By the time I said those words, nearly half of the monster's long-haired head managed to regenerate. At the same time, most of my companions was already standing up to their feet and grabbing their weapons. Yet, it was pretty obvious that if I were to wait for them to gather up and attack the maere, it would be way too late.

So I pulled out one of the fancy stones prepared by Sander, pressed the activator, and threw it towards the monster. At first, it was clearly wary of the projectile, jumping away. Thankfully, its female part hampered its escape, dragging it down. Yet, instead of smashing the monster apart, the stone just fell to the forest bed in front of it, doing absolutely nothing.