Attack on Titan has built a cult following over the years. The series' cryptic nature meant fans were never fully in the know about key plot points and information that was regarded as fact in one season could be disproved as the characters learned more about the world around them in the next. Former enemies turned out to be surprising allies, and vice versa.
The secrecy and long breaks between seasons have led to fans of the anime constantly trying to predict what direction it'll take next, from character arcs to motives, before they're actually explained. Success has been mixed. Some theories have ended up being proven right as events continue to unfold while others couldn’t have been further from the truth. From Titan armies to time-traveling characters, here are a few of the wildest Attack on Titan theories fans have come up with.
To You, 2000 Years From Now
This is one of the more confusing theories -- and one already proved (mostly) false -- but it’s still fun to ponder over. According to the theory, Eren is only the protagonist because he is a time traveler, unaware of his past due to his memories being repressed by his journey through time.
The theory continues that the events of Attack on Titan happen in a time loop that begins when Eren regains the memories of his futuristic origin. He remembers that the time he was born in as one where humanity is under complete control of the Titans and is on the verge of extinction. In a bid to prevent that future from ever happening, Eren pens a letter to humanity in the future, revealing his status as a time traveler and detailing his experiences of the present.
He also explains all the signs foreshadowing the eventual Titan domination to come, beginning it with “To You, 2,000 Years From Now,” which is the title of the first Attack on Titan manga chapter and anime episode.
After writing it, Eren seals it somewhere safe where it will not be disturbed until the time is right. Humanity, in the future, after reading Eren’s letter, realizes that time travel is possible and scrambles to perfect it in order to prevent the oncoming Titan disaster. They send back as an assassin to kill the scientist responsible for creating the Titan serum, Grisha Yaegar, but the assassin fails, and in a freak accident, ends up granting Grisha the compounds he actually needed to create the Titan serum.
History continues unchanged and the Titans rise, forcing humanity to live in constant fear of them. The time loop is completed when a descendant of Mikasa transports her son, Eren, back in time to save him from the Titans. Eren asks if Mikasa's hair is longer when he wakes up in the very first episode (and chapter) because his last memory of "her" was actually her descendant who sported a shorter cut.
The Secret of the Basement
Grisha Yaeger’s locked basement was, for a long time, a huge source of speculation among fans; each theory as unlikely as the next until the Scouts finally made it to the basement. One of the more tame ones (if you can believe it) claimed Grisha was hiding computers and other more advanced technology in it that held the secrets of the Titans, as well as instructions on how to create the serum responsible for turning people into Titans.
The theory also states that Grisha was only able to rid the Shiganshina townsfolk of the plague because of his advanced knowledge and technology. Another theory claimed he was a 'mad scientist' hellbent on creating some sort of super-soldier serum, and that the Titans that populated the world outside the walls were a result of his failed human experiments. Yet another theory claimed that Grisha was hiding a Titan army down there and that he meant to give Eren command of them when he returned from his trip.
Grisha Yaeger himself was also a lightning rod for numerous other theories. Some fans were convinced Grisha was the Colossal Titan, simply because the lightning that struck right before its appearance was the same color as Eren’s when he transformed, and he bore a passing resemblance to the Shifter.
The Beast Titan Theory
The second Attack on Titan season arrived four years after the Season 1 finale, giving fans enough time to theorize their hearts out. But most of them went out the window with the debut of the Beast Titan. His first appearance brought with it a slew of theories about his origin, as well his plans for the people within the walls.
One such theory put forward that the Beast Titan, dubbed "Monkey Trouble" by fans, is the creator and lord of all the Titans in existence. Centuries ago, when humanity fled to the safety of the walls, the King entered an agreement with the Beast Titan. He was supposed to send a certain number of people over to the Beast as sacrifices, and as long as the Beast continued to receive his due, the safety of the walls would not be threatened. The theory goes on to suggest that the King became unable to send the Beast’s usual payment for fear of being found out by the Survey Corps. Under Erwin Smith’s leadership, the military faction was closer than it had ever been to uncovering the secret of the Titans, and the King was well aware of that.
Since he hadn’t received his due in a while, the Beast Titan launched an attack on the people within the walls as punishment. The theorists believed he specially created the Colossal, Armored and Female Titans and gave them the power to shift in order infiltrate the humans and weaken their defenses. The reason he’d finally shown up himself was to deliver humanity’s last judgment.
The Beast Titan’s unique abilities and presence led further credence to the idea, as he was shown to have control over the Pure Titans. His simian appearance and ability to communicate with humans were abilities that, until now, were exclusive to him. This is another that hasn't panned out, but at the time, it didn't seem improbable.