With any luck, his own.
But that's not the idea. The two adversaries are lashed together by one wrist each so they can't get away from each other. The other hand holds the blade. Your opponent's wrist is typically not the best target in such a scenario.
I completely understood that. I was breaking funny.
I recall reading a biography of John Wesley Hardin 40+ years ago, and the writer described a knife fight Hardin got into that was similar to that.
It was so horrifying that I’ve never forgotten it.