Out of all four elements in Avatar: The Last Airbender, fire is the one most closely tied to emotions. If a fire bender is not in tune with their emotions, they cannot effectively bend. An example of this is when Zuko was unable to learn lightning generation due to his emotional turmoil. This doesn't occur with the other elements. Firebending is a reflection of the personality and emotions of the bender. This is especially true with Princess Azula.
Azula is a unique kind of firebender in the world of Avatar. The flames that she produces are blue instead of the usual yellow or orange. Many fans assumed that this simply meant Azula's fire was stronger than normal, as blue fire is hotter than yellow or orange fire. However, this idea doesn't quite tract. No other firebender has ever used blue flames. The Avatar, the strongest bender in the world, couldn't use blue flames even when amplified by Sozin's Comet. So if the blue fire doesn't represent greater power and it's not genetic -- as no one in her family can replicate her flames -- why can Azula specifically create blue fire?
Azula's Fire is Fueled by Cruelty
Azula was one of the most compelling antagonists in Avatar. Her personality and the way she interacted with others were always interesting. The relationship between her and Zuko also helped to highlight the differences between them. However, these attributes also made her uniquely evil when compared to other villains. Other villains were driven by a lust for power, prosperity for their nation or revenge for a wrong committed against them. That's not what drove Azula.
The princess of the Fire Nation enjoyed hurting others. The misery and suffering of others pleased her even when it didn't directly benefit her. Azula often gleefully bullied Zuko for her own amusement when they were children. She even taunted Zuko when she found out that their grandfather had sentenced him to death and sadistically smiled when Zuko was burned by their father. Even the power-hungry Ozai never displayed a level of sadism equal to Azula.
It's possible that Azula's cruelty and hatred caused her flames to turn blue. She funneled all her negative emotions into her firebending, causing it to change colors. It's been shown that Azula's firebending wasn't always blue. When she was a child, her flames were the same color as every other firebender. The fact that Azula is the only known firebender with blue flames shows just how cruel she truly is.
What Do the Different Fire Colors Mean?
The series repeatedly shows that a fire bender's emotions determine the strength of their fire. When Zuko was first teaching Aang how to firebend, both of them had difficulty. Aang was too afraid of losing control and Zuko no longer had enough hate to produce strong flames. Aang and Zuko had to learn a new method of firebending from the dragons, the original firebenders.
It was originally assumed that hate and aggression were needed to firebend, but the dragons proved otherwise. The dragons produced rainbow-colored flames and showed Zuko and Aang the life-giving qualities of fire. Firebending can be fueled by any emotion or drive, including the desire for peace. It's possible that if the drive or emotion is strong enough, it can change the color of the fire, like the rainbow color produced by the dragons.
If this theory is true, it would explain how Azula's fire changed to blue. Because cruelty and hate were her main purpose and drive, it corrupted her fire. As Azula grew older and became more evil, her fire changed into the iconic blue color that she's known for now. This change highlights the differences between her and her brother. Even when Zuko was at his darkest moment and filled with nothing but hate, his fire never changed colors. This shows that he was still able to be redeemed.
Can Azula Ever Be Redeemed?
Now that Azula's fire is blue, she may be too far gone. Unlike Zuko, she hasn't shown any amount of regret for her actions or empathy toward others' suffering. Even as a child desperate for his father's love, Zuko was still willing to defy Ozai when he planned to sacrifice soldiers. Zuko never enjoyed causing pain to others, but for Azula, that's her main source of enjoyment. It may be impossible to free Azula from her darker self.
Alternatively, if Azula chose to rethink her life and humbled herself, she might be saved. She could go through an arc where she decides to relearn firebending like Zuko and Aang. This could act as a form of therapy for her. Through this, she would learn how to open up her mind and find a new fuel for her firebending that's not cruelty. Azula is a character with a lot of potential. Whether she falls deeper into evil or finds a way to redeem herself is all her choice.
