While it might be years old at this point, Avatar: The Last Airbender is one of the greatest cartoons of all time (and eclipses the rest of the roster on Nickelodeon). Featuring brilliant characters, a universe packed to the brim with interesting lore, and episodes that are worth watching and re-watching over and over.

The creators had something special on their hands, and despite a sequel series (The Legend of Korra) having come and gone, the original project still remains the better of the two. It has inspired people to search further and become more invested in this fictional world.

Despite how rich Avatar: The Last Airbender was, though, the show itself didn't answer all of the questions that were raised. What became of Zuko's mom? Who remained a couple and who didn't? Apart from that, there were other secrets buried underneath the layers of the show that you wouldn't figure out unless you did the proper digging.

Dig no more, because we've uncovered 20 dark secrets about Avatar: The Last Airbender that you never knew. Get ready to round out your knowledge of Aang, Zuko, and the rest of the gang and dive back into this phenomenal world once more.

20 Sent Off To The Asylum

Azula was one of the fiercest foes in the show. Between her blue fire, sinister demeanor, and ability to conjure lightning, it seemed that there was no beating her. However, something that came about near the end of the show was that she had one fatal flaw: her mental stability.

Despite portraying herself as cold and unfeeling, Azula had drastic effects from being unloved by her mother and being feared by even her closest friends. In the series finale, she ended up losing her mind and her composure. After the show ended, Zuko had her taken to an insane asylum, where she spent the rest of her days. However, the two siblings would later meet up and Zuko still cared for her.

19 An Early End

Avatar Aang stopped the Hundred Years War, but the only consequence is that he was gone for most of that time. After being frozen for a century, he was awoken as a twelve-year-old and ready to fight the Fire Nation and master all of the elements. In that time, he learned to embrace his destiny as the Avatar and bring balance to the world even after the fall of Phoenix King Ozai.

That said, Avatar Aang's aid on the world wasn't as long as a normal Avatar's life. All of those years spent trapped in a block of ice caught up to him, leading to a body that decayed at a much more rapid rate. Aang was around the age of 60 when he died, which explains why some of the old cast members appeared in The Legend of Korra.

18 The Couple That Never Was

Ever since the first episode, it's always been hinted at that Aang and Katara would eventually become a couple. The Avatar's unrequited love for the young Waterbender was both charming and hopeful. Yet, it wasn't always the original plan to have these two get together by the time the series ended.

At the end of season two, Katara and Zuko spent some time locked up in the crystal caves together. It's there that Katara learned about Zuko's tortured past and she nearly healed his scar with the spirit water. The writers were going to take this further, but later decided against it and felt that having her be with Aang would fit the context of the story better.

17 A Real-Life Inspiration

When Team Avatar arrived at the great city of Ba Sing Se, they were quickly met with opposition and a dark conspiracy to overthrow the Earth King. The agents of the royal palace, the Dai Li, were assigned to bring any troublemakers to a facility called Lake Laogai, where they would be brainwashed and released back into the city.

As scary as this was, Lake Laogai has some real-world inspiration. Laogai was the name of many Chinese labor camps where people would be forced to do extreme work and succumb to severe torture. While they weren't directly brainwashed, the people at this camps would have drastic mental side effects that led to sad deaths in the end.

16 Bosco Deserved Better

Instead of opting for entirely unique creatures, Avatar: The Last Airbender has critters that are combinations of animals that we know and love (such as the platypus bear and lemur bat). One exception to this rule was the Earth King's personal pet bear named Bosco. It was a cute and cuddly creature that later traveled the world while Ba Sing Se was taken over by the Fire Nation.

Fast forward several decades later to the narcissistic Earth Queen who ruled Ba Sing Se in The Legend of Korra. There were stories passed around that she ate an animal in the past, and judging by her age, all implications point to her devouring Bosco in an attempt to take the throne for herself. If that's the case, we're glad she was outed by Zaheer.

15 Pushing Away Those You Love

Zuko struggled with his actions throughout the show. When he eventually decided to leave his life in the Fire Nation to join Aang, he had to suffer some consequences along the way. Among them was sacrificing his relationship with Mai. Luckily, the two later reunited and became a couple after the Hundred Years War ended.

Things weren't all rosy for the couple, though. Zuko had to deal with the pressures of being Fire Lord as well as the influence of his father and sister. He kept Mai out of the loop several times, and she felt so pushed away that she eventually left him. However, the writers later said in an interview that at some point after that, Zuko and Mai came together once more.

14 Whatever Happened To Suki?

Sokka was always a wildcard in terms of his love life. It could go multiple ways for all the audience was concerned. However, when the show was nearing completion, it was the leader of the Kyoshi Warriors, Suki, that ended up capturing his heart. At the end of the series, the two of them were shown to be together, but things are a bit unclear after that.

Suki and the rest of the Warriors served as the personal guard to Fire Lord Zuko, but she didn't interact with Sokka very much. There is no further information on her whereabouts or how she died, so it's all left up to the imagination. There's also a theory going around that Sokka ended up with Toph, but that hasn't been confirmed or denied either.

13 A Lost Spirit

The Fire Nation was full of people who had no clue of how to maintain balance in the world. They just wanted to see the world under their own banner. A prime example of this is Admiral Zhao: a central antagonist that appeared during season one. He made it his personal mission to siege the Northern Water Tribe and even killed the Moon Spirit in the process. However, he was killed by spirit water in retaliation and was never heard from in the show again.

In The Legend of Korra, we got our answer as to what happened to Zhao. He ended up in a place in the Spirit World known as the Fog of Lost Souls. It was there that he was focused on capturing the Avatar and bringing him to the Fire Nation. However, it became clear that his mental sanity was long gone.

12 A Dark Pact Among Friends

Zuko came from a long line of people that wanted to screw up the world. Because of this, there was a lot of pressure on him to do things right, and he was intent on helping restore balance to the rest of the world. He had a close relationship with Aang after the Hundred Years War ended, but it wasn't all sunshine.

Zuko saw how the politics of the world were changing during the fall of the Fire Nation, and was scared of what he would become. This led him to make Aang promise to kill him if he ever remotely turned into his father. Naturally, this put the Avatar in a bad spot, as he couldn't even kill Ozai, let alone one of his best friends.

11 Eternal Life

General Iroh was always a fascinating character. Despite being the brother of the Fire Lord and mentor to Prince Zuko, he was never depicted as a bad character. Even during the siege of the North Pole, he attacked Admiral Zhao for killing the Moon Spirit. He would later lead the Order of the White Lotus as they took Ba Sing Se back from the Fire Nation.

However, due to his age, Iroh wasn't long for that world after the war ended. Yet, he never died a traditional death. Being in touch with the spirits, Iroh was allowed entrance into the Spirit World and remained there for eternity. He later appeared in The Legend of Korra when the new Avatar got lost in the unfamiliar scenery.

10 A Difficult Confrontation

Fire Lord Ozai wasn't exactly the most loving person on the planet. Yet, this didn't stop him from having a wife named Ursa. She was an increasingly caring person and taught Zuko all of the big lessons that he learned in life. Yet, after one fateful day, she disappeared and was no longer present in the Fire Nation.

While everyone presumed she was dead, Ozai revealed to Zuko that she was actually alive, and after the Hundred Years War, he and the rest of Team Avatar left to find her. They eventually brought her back to the Fire Nation, where she went to confront Ozai after all those years. Stating how much of a small man he was, she left the room with him begging for her to come back and submit.

9 The Fire Nation Colonies Weren't Disbanded

As the Fire Nation expanded their reach in Avatar: The Last Airbender, they began taking over territories in the Earth Kingdom, becoming known as the Fire Nation Colonies. Naturally, the Earth Kingdom wanted them disbanded after Ozai was taken down, and Zuko was originally open to this idea.

However, as he began to assume the duties of a leader, he began to question whether or not that was the right decision. As a matter of fact, he chose not to disband them at first, further emphasizing the Earth Kingdom's anger at the Fire Nation. Avatar Aang eventually had to get involved, and everything else went downhill from there, at least for a time.

8 Fatherly Advice

Fire Lord Ozai could never win the father of the year award, and proof of that is all over Zuko's face. Not only did he serve as the primary antagonist of Avatar: The Last Airbender, but was a source of conflict within Zuko. Despite the fact that Ozai was his father, he knew that the Fire Lord had ill intentions.

Still, even after all of that Phoenix King nonsense, Zuko actually visited his father in prison. After all, he had no idea how to run the Fire Nation and knew that Ozai had experience. However, the little counseling sessions didn't last long, as the two quickly had a difference of opinion and Zuko stormed out and never listened to his father again.

7 Promoting Segregation?

Throughout Avatar: The Last Airbender, Aang learned that the separation between the Four Nations was nothing more than an illusion. Guru Pathik even taught him that everyone was connected in the world. Because of this, Aang sought to unite all Nations under one banner so that they could live together in balance and harmony.

However, when the debacle with the Fire Nation Colonies arose, Aang saw how much dissension there was between the Nations. There were even people who began drawing the Airbender tattoos to mimic Aang, which he found repulsive. Because of this, he decided for a time that the only way to solve the problems in the world was to keep the Four Nations separate, despite the counsel of Katara.

6 A Severed Connection

Aang wasn't alone when he resurfaced after one hundred years in a block of ice. Other than having Sokka and Katara to back him up, he had the wisdom of his past lives, mainly the previous incarnation, Avatar Roku. Roku served as his primary guide throughout the series and gave him many lessons about what he could do defeat the Fire Lord and master the four elements.

Things didn't stay that way, though. After the Hundred Years War when Aang was under that promise to kill Zuko, tensions rose and he was faced with that decision. Roku told him that it was his responsibility to do so and by not killing the Fire Lord, he caused more imbalance for the world. Aang believed in his cause, though, and literally broke his connection with Roku, thus leaving himself on his own.

5 History Repeats Itself

The story of how the Hundred Years War began is a tragic one. It started with two friends, Fire Prince Sozin and Roku. However, once Sozin became the Fire Lord and Roku became the Avatar, their dynamic was forever changed. Sozin had a view of what the world would be like under one banner and tried to conquer it. Naturally, Roku had a thing or two to say about it.

Sadly, this conflict between the friendship of the Avatar and the Fire Lord would be repeated. Aang and Zuko heavily conflicted after the Hundred Years War, in the debacle of the Fire Nation Colonies. Zuko seemed to have gone tyrannical, and Aang had to make the choice of whether to kill the Fire Lord or let him live. Thankfully, he took his classic route and found a third option by hearing Zuko out.

4 This Marriage Was Never Supposed To Happen

One of the biggest questions that we have when watching Avatar: The Last Airbender is: how did Ozai marry such a kind woman? The answer is that it wasn't really her choice. Ursa was in love with a man named Ikem, but one day, was visited by Fire Lord Azulon. He stated the utmost importance of keeping the royal bloodline intact and she was forced to marry Ozai as a result.

Because of this, she was never happy in her marriage, as she was forced to leave her old life behind and never see her friends or family again. She constantly looked back to her younger days with Ikem and wished that there was some way she could be with him again. Eventually, she got her chance to reignite that love.

3 The Hallucinations Never Stop

As Azula began losing her sanity, not only did she lose her composure, but she began to hallucinate. What did she see? It was nothing other than her long-absent mother. She felt that her mother viewed her as a monster, but her hallucinations said otherwise. This only drove Azula further into madness, and it wasn't helped by her stay in the mental institution.

When Zuko visited her again, not only did she look worse, but she continued to hallucinate visions of Ursa. She was brought along to find her and Zuko's mother, and she nearly got herself killed by hallucinating once more. This further drove her into madness and proved that all she really wanted, in the end, was to be loved and accepted by her mom.

2 There's A Reason For The Hatred

It seemed throughout the series that Zuko, no matter what he did, was always going to be a disappointment to Ozai. He adored Azula because of her ferocity, but detested Zuko because of his humanity. However, his hatred of his own son goes a bit deeper than capability in battle.

Shortly after Ursa married Fire Lord Ozai, he was led to believe that Zuko was the son of her lover Ikem instead. While this was revealed to be a lie from Ursa, as she merely wanted to believe that she had a son with Ikem, Ozai never let it go. He said that he would treat Zuko as an illegitimate child that came from a different father unless he proved himself enough to be accepted into the royal family.

1 Responsible For This Dark Act

Zuko Alone is not only one of the best episodes of Avatar: The Last Airbender, but it shows us a better look at what happened in his childhood. Ozai wanted the throne, which belonged to Iroh. His father Azulon was so offended that he requested that Ozai know what it was like to betray his firstborn son by ordering him to kill Zuko. Instead of that happening, Zuko awoke the next morning to find that his mother had disappeared.

While we know where she went, we're not exactly sure what happened that caused her to leave. As it turns out, Ursa didn't want Zuko to die and promised Ozai that she would concoct a poison to kill Azulon. As a result, Zuko would live, and she would leave the Fire Nation for good. While she didn't poison Azulon herself, she gave Ozai the means to ascend to the throne.