It disables it to the point where even the greatest healer in the world, Katara, could not fix it. (Aka, taking it away) The question being as is who are the top three benders of each elements, and with pure intent to kill. Amon is unaffected by Bloodbending as seen when he faced his brother. So he can easily defeat his brother (as seen) and his father who is about as strong as his brother. Amon was also able to manipulate bloodbanding, and waterbending without movement, do a degree able to affect incoming attacks so they will be easier to avoid. With the Pure Killing intent, against any other waterbended he is outmatched.