Kohrak Kal has sonic powers which can be very dangerous. Onua normally wouldn’t be able to handle such an onslaught and would be overwhelmed by the quick (yet deadly) attacks. Having sonic powers can be incredibly useful and can propel many fighters to new heights. Even so, Onua has his fusion form, which saves him from utter destruction. It’s always useful to have a trump card in the mix. Onua wins.