It's been over a decade since the manga's first chapter was released, and Attack on Titan is coming to an end in less than a month. Fans of the series are sad that there won't be any more chapters in one of the greatest stories ever written and excited to see how the journey that Hajime Isayama took them on will end.

RELATED: Attack On Titan: 10 Best Manga Volumes, Ranked (So Far)

While they wait for chapter 139 to come out, some fans have been thinking about how the series may end. Many theories are going around, but nobody knows for sure what Isayama has planned. With all of the twists and turns included in the Attack on Titan series, however, it wouldn't be that far-fetched if some of these wild fan theories were true.

10 The Eldians Will Explore The Outside World

Attack on Titan Wall

Now that a huge percent of the population has been killed and many of the Eldians' enemies have come to see that they were wrong for hating and fearing the people inside the walls, the Eldians may finally leave their country. When the series began, most of the people in Paradis were afraid to go outside and resented the Survey Corps for doing just that. However, without a reason to be afraid, they may finally feel the way that Eren, Armin, and the other soldiers felt.

9 The World Will Hate Eldians More Than Ever

The Corps in Marley AOT

While there are people who understand that they were wrong to treat Eldians so poorly, there will probably not be others who will not accept how their actions resulted in The Rumbling, solely blaming Eren and the people he once fought with. One of the best things about Attack on Titan is how many perspectives there are over the same situation, with fans understanding how nearly every character feels. It would make a lot of sense that while the Eldians don't have as many enemies as they did before, the ones they still have will hate them even more.

8 The Entire Series Is A Story That Armin Wrote

armin beach attack on titan

Armin has always been a big reader. When he was a child, he found a book about the world outside of Paradis and showed it to Eren, which is how they first got curious about what was beyond the walls. When Armin was inside the coordinate with Zeke, he told him that one of the things that made life worth living for him was reading a good book.

RELATED: Attack On Titan: 10 Happiest Scenes In The Series, Ranked

It wouldn't be a surprise if Armin either wrote down all of the series's events as a nonfiction story or if everything that happened was something he made up, especially since his voice actor is the narrator of the anime. Fans have always believed he couldn't die, but what if there wasn't even anything to kill him?

7 Historia's Child Is The New Beast Titan

Beast-Titan-AOT

When an inheritor of the Nine Titans dies, their power will go into a baby upon their birth, as long as they weren't eaten by a person that turned into a titan. Seeing how Zeke was killed when Levi decapitated him, his power will be sent over to a newborn Eldian. Fans have known that Historia has been pregnant for a while now, and she was about to give birth the last time she was seen. By now, the next member of the royal family could already be born. Since this child is a distant relative of Zeke's, it'd make a lot of sense if this baby became the Beast Titan.

6 Jean, Connie, And Gabi Will Become Titan Shifters

Gabi, Jean, and Connie titans

In chapter 138, Jean, Connie, and Gabi all became titans and the Eldians that weren't titan shifters at Fort Slava. These new titans started attacking Reiner, Annie, and Pieck, with many readers noticing that Connie and Jean were eating Reiner. Jean, Connie, and Gabi may become the next Cart, Armored, and Female Titans, especially Jean, as he was biting Reiner at the back of his neck. It'd be interesting if, after all this time, these three inherited a titan in the final chapter.

5 Eren Wanted To Lose

Eren says "freedom"

Though Eren's goal may have seemed to have The Rumbling destroy the world outside of Paradis, it may actually be that he wanted to lose. He always wanted his loved ones to be free, and by having them save the world, they would no longer be in danger from Marley or any of the other countries that feared the titans. This would especially make sense since he allowed them to fight against him when he could have easily removed their powers since he is the founding Titan's inheritor.

4 Ymir Will Get Rid Of The Titans

Ymir Fritz

The titans would never have existed if it weren't for Ymir. After she stole a pig, King Fritz sent his men to hunt her down. She ran inside a tree where she connected with the Source of All Living Matter, becoming the first titan shifter.

RELATED: Attack On Titan: 10 Worst Things That Happened In The Manga In 2020

After she died, she ended up inside the coordinate and was forced to create titans for centuries. Now that she is back in the real world, she may decide to get rid of all of the titans and end the 2,000-year war.

3 Eren Is Still Alive

Eren Yaeger (Attack On Titan): A Good Guy Who Eventually Turns Numb To Killing Innocent Humans

Eren has survived getting shot in the head by Gabi, being blown up by Armin, and countless other dangerous situations. Though it really does seem like he is dead now, that's not necessarily the case, and Isayama could surprise readers one last time. Whether it be that he's in Paradis and is using his War Hammer Titan to control the Rumbling like many believe or if the Source of All Living Matter will attach to him one last time, Eren could still live for another four years, when the Curse of Ymir would probably, finally kill him.

2 Eren Goes Back In Time

Eren wakes up

The first time readers saw Eren was when he woke up to see Mikasa above him. He was confused as he had a nightmare that caused him to cry but couldn't remember anything about it except Mikasa's short hair. In recent chapters, Eren as a child has been seen more, so he could very well be dreaming of the present and lose his memory when he wakes up. To make this theory even more interesting, there was a mysterious scene in chapter 138. Eren and Mikasa had escaped the war between Paradis and Marley and started living on their own. The last thing that Mikasa says in this scene is, "See you later... Eren", which she also said in his dream.

1 The Entire Series Has Revolved Around A Time Loop

Earth Devil and Ymir Fritz

Historia cared most about in the world was Ymir, and it wouldn't be a surprise if she named her child after her. Seeing how Yeagerists have taken over Paradis, Eren may become the new king of the walls and overthrow Historia. If he doesn't have a child, a Yeagerist may take the crown and turn out to be King Fritz. One day, this new Ymir will steal a pig, leading her to come into contact with the Source of All Living Matter, and the entire series will repeat itself.

NEXT: Attack On Titan: 10 Spin-Offs That Should Be Made After The Series Ends