10 Greatest Avatar: The Last Airbender Moments
6. Katara Confronting Her Mother's Killer - The Southern Raiders
The death of Katara's mother haunts her from the very beginning of the series. The trauma of such a loss defines most of her entire character. It's what fuels her hatred of the Fire Nation, it's what drives her to act like the den mother of the group etc.
So of course, when Zuko offers to help her find her mother's killer as an olive branch to mend the trust he broke in Ba Sing Se, Katara immediately takes him up on it, determined to make the man feel a fraction of the pain she's carried her entire life.
But the real genius of the episode comes when she DOES confront the killer. She finds a pathetic, sad, empty husk of a man that she just can't bring herself to do harm. Not out of forgiveness, she makes clear that she will NEVER forgive him for what he did. But instead she just can't bring herself to waste her time and powers snuffing out a life that had clearly been drained away a long time ago, if it was ever there at all. In cases like these, it's crueler to leave the bastard alive.
This confrontation is one of the most important moments for the character of Katara, and is a brilliantly harrowing and haunting scene besides.