Frisk might be good at dodging. They might be very good at dodging. But dodging a mini-tsunami? Okay, yeah, that would be hard at the best of times, and it was impossible when they were directly next to the medusa. They're knocked back by the Waterga, tumbling head over heels, and they eventually come to a stop covered in bruises, as well as a few fractured ribs. They're not angry about that, though. They're angry when they see Papyrus hurt. "Papyrus!" they yell at the top of their lungs, disappearing in a Smoke Bomb and reappearing at his side.