Klonoa is just glad that he threw that barrier up just before they all got hit. He grits his teeth, and stumbles back, letting himself get thrown. He manages to stick the landing pretty well, but when he looks up--okay, Frisk is gone, that's probably not ideal.

"It's alright everyone, we'll get through this!" He calls out encouragingly, clapping his hands together. If nothing else, he can get Castor healed up. But why just heal her once? He casts Regen so he can heal her without having to heal her!