Big Brother Instinct: After the fall of the Fire Nation, Zuko busies himself with looking after a catatonic Azula and trying to find a new home for them both.
Moral Event Horizon: When Crescent Island starts to erupt, Azula orders the warden at the Waterbender Prison to seal up the prison chamber that houses the cages for the Southern waterbenders. This despite knowing there's a prisoner her age in there.
You Fight Like a Cow: When fighting against Katara for the first time, Azula insults the younger girl's sloppy technique, fully knowing Katara's weaknesses from having been locked up in a cage for a decade.
Ozai
Dead All Along: By the time the story events in the present take place, Ursa has killed him and replaced him with a masked version of herself, a fake magical identity gained from the Mother of Faces.
Zhao
Glory Hound: It's Zhao we're talking about. It should be no surprise.
Kick The Son Of A Bitch: Betraying and killing an ally would be pretty bad... If it wasn't Yon Rha, who saw little problem with imprisoning a 5-year old.
It's All About Me: Even if it means dooming the world, Iroh will not give up Lu Ten's life.
Papa Wolf: Deconstructed. Iroh is willing to throw the world out of balance to keep his son alive.
Ungrateful Bastard: Killed Yue's father even after Yue helped resurrect Lu Ten.
Azulon
Lo and Li
Yon Rha
Asshole Victim: Zhao betrays and murders him. But really, after imprisoning a 5-year-old girl just for being a waterbender, no one is gonna feel sorry for Yon Rha.
You Look Familiar: Has these thoughts after meeting an older Sokka face to face. They have indeed met, as Yon Rha took Katara away right before Sokka's eyes ten years beforehand.