I think it would work better if they freak out, do the impression of 'The Scream' and then explode into gibs.
Now for a Genma Fatality.
DUN DUN DUN...
Genma pours a kettle of cold water on himself and turns into Genma Panda.
Then he pulls out one of his signs and scribbles something on it, then shows it to his opponent. Said oppenent recovers a bit and walks over to read it.
Then Genma snaps the sign back with a flick of his panda wrist and smashes his opponent like the thing was a fly swatter. Opponent drops to the ground with their neck snapped. Genmat tosses the sign over his shoulder, and does the Kenshiro pose from fist of the north star.
GENMA... PANDA, WINS!
FATALITY
"Growf!"