Karuna claims himself to be the greatest swordsman on Koholint Island. He duels Link shortly after the hero exits the Angler's Cave, but Link's broken sword is no good against the swordsman. The ghost of Nakura arrives and saves him after Karuna knocks him off a cliff.
Later, Link duels Karuna again, now equipped with Nakura's sword. In this encounter, however, Link prevails, and kills the Moblin.