Agree, he might have changed him thinking and become a good man.
To azndude945 : Zabuza is a Missing-nin formerly from the Hidden Mist Village, and the first major baddie that Naruto and team face after graduating as Genins. He is a close friend of Haku, and (being a mist nin) most of his Jutsus are water-oriented. He is also known as 'Devil of the Hidden Mist' since in the Hidden Mist Village, there used to be a final Genin graduation exam - a one-on-one fight to the death. However, one day, without pause or hesitation, a young man who was not even a ninja killed over a hundred of the students. That young man was Zabuza. The one-on-one system where best friends are forced to kill each other was abolished after this incident. Zabuza is a very powerful Jounin, as we see in the fights between him and Kakashi. One of his specialties is 'Water Prison' - a large ball of water that he uses to imprison his opponents, not so much powerful but very affective.
Zabuza appear during Haku time..not sure which epi, maybe someone can highlight.
Ma Sis : Sakatsu, Bubblezio