Mo Fan originally thought that he could easily win by traveling through Hokage with the krypton gold system.
But when he tried to use Dragon Ball Qigong Wave to instantly kill Zabuza, the system prompted that the balance was insufficient.
Seeing Kakashi trapped in the water prison, he gritted his teeth and bought the cheapest skill - a 100% fall in a funny show.
Just when everyone was desperate, his foot slipped, and the kunai accidentally cut off Zabuza's chakra line...