The moment Klaus' outstretched hand brushes the crystal, a burst of energy shoots into his body. His body becomes lighter, and he involuntarily rises up onto the balls of his feet. He feels as though he might float up off of his feet at any moment. When he looks over, he sees that Estraeah has also went for one of the purple crystals.
The last thing he feels before losing consciousness is a gust of wind, inexplicably flowing though the cavern and ruffling his hair and clothes. He does not feel himself hit the ground.