So she didn't have control of it. That was fine, as he doubted whatever it was could be tremendously dangerous to him. Still, it was an annoyance. He approached her, dodging a few more bits of the thing as he went. If he had a better idea of what was going on, he might have been able to do something to stop it, but as it stood the best he could do was try to make Yako get a grip on it. He knelt down next to her and placed a hand on her shoulder, bracing for any unexpected effects that might cause.
"I'm not here to hurt you. Calm down." Even if trying to calm her down didn't help, whatever happened might give him some insight into the nature of this power she seemed to have developed.