I would venture the Scrapyard Yard Hook
would be the best of the Scrapyard knives as a fighter.
It has that "hook" which is a blade catch.
Another knife blade sliding down your blade would be "caught"
and you could,in a twisting motion,disarm your opponent.
Me,I'd run... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />