Confirmed Theories and facts.
- All Titans were once human. Most have been fully absorbed by their Titan form, with only the central nervous system remaining as the weak point in the nape.
- The Titan Shifters' goal was to locate the Coordinate.
- The Beast Titan is responsible for the destruction of Ragako, by transforming the villagers into Titans.
- The Titans within Wall Rose were the villagers from Ragako. The House Titan is Mrs. Springer.
- Eren has the Coordinate ability, which allows him to control Titans.
- It is possible for a Titan to regain their mind and human form, as evidenced by Ymir regaining human form after 60 years.
- At least one other settlement exists outside the Walls.
- Ymir is a surviving member of a group destroyed by the group Reiner, Bertolt, and Annie serve. She gained her powers by stealing it from them.
- Titan form is a potential Lotus-Eater Machine, hence their commonly blissed-out expressions.
- The King (King Fritz. "Fritz" is his family name or name of the dynasty he belongs to, despite "Fritz" being a German first name) is a Fake King and the real royals, who used to be Fritz, changed their name to Reiss.
- Krista/Historia's family is deeply involved with the Wall Cult.
- The masters of the Titans, or the intelligence behind the Titans' actions, is in a faraway location, along with other Titan Shifters.
- Levi and the man who murdered Historia's mother share the last name Ackerman, suggesting at least a distant paternal relation to Mikasa.
- Hannes will once again face off against the Titan which killed Carla.
- Hannes will die fighting against the Titan he was too scared to do so before.
- In one way or another, Levi and Mikasa are related.
- Reiner, Bertolt, and Ymir all have knowledge of the Beast Titan.
- The "Coordinate" is not just the ability to control Titans, it's the ability to Mind Control almost anyone.
- Normal Titans eat humans in an instinctive attempt to devour a Shifter in order to return to their human form.
- Eren is not the Coordinate, because the Coordinate is not a person (It is a power passed from host to host, possibly by devouring the host).
- Marcel/Berwick was a Titan Shifter, and Ymir became a Shifter via Cannibalism Superpower.
- Captain Ackerman raised and trained Levi.
- The Reiss family intended to have Eren eaten, in order to place the Coordinate in a more suitable host.
- The injection Grisha gave Eren is responsible for his Titan powers.
- Eren ate Grisha to become a Shifter.
- Eren's Titan form inherited its pointed ears from Grisha's Titan form.
- Grisha himself was a Titan Shifter.
- The mysterious woman from Historia's forgotten memories and Eren's flashbacks is Historia's older sister, Frieda, who was a Titan Shifter with "incredible power." She could remove people's memories.
- Grisha devoured Frieda in order to gain her power, and then massacred all members of the Reiss family except Historia and her father.
- Frieda's power was passed onto Eren through Eren eating Grisha.
- Rod Reiss intended to turn Historia into a Titan and trick her into eating Eren, the same way Grisha tricked Eren into eating himself.
- Certain bloodlines- including many noble houses- are not affected by the memory-altering ability held by members of the Reiss family.
- When the walled city was built, its citizens' memories were altered by a Titan Shifter carrying the "Coordinate" ability. The same Titan Shifter also built the walls surrounding the city and the cave Eren was held in awaiting Historia to devour him to gain his "Coordinate" ability and use it to its full potential.
- Frieda's "incredible power" is the "Coordinate" ability.
- The Beast Titan is a Titan Shifter.
- Keith Shadis was the one who sabotaged Eren's Three-Dimensional Maneuvering Equipment during training.
- Some Titans can move at night using the reflected sunlight from the moon as fuel. Whether these Titans are simply unique or the result of a new formula remains to be seen.
- Marco was murdered through the combined efforts of Reiner, Annie, and Bertholdt, for overhearing a conversation that revealed their true nature.
- The Beast Titan (aka Zeke) is aware that Humanity's memories were altered by the First King.
- The Military Police Brigade suppressed the technological development inside the walls (e.g. when they confiscated a hot air balloon, advanced firearms and other stuff and killed the inventors)
- Humanity is far from extinct, and is in fact thriving outside the walls. The walls are contained on an island called "Paradis" which, based on maps of the island, appears to be the series' counterpart to Madagascar.
- However, the nearby continent is completely controlled by a nation with many commonalities with Nazi Germany - and the ethnic group of those inside the walls can be compared to the Jews in their eyes, so they still face potential extermination since Humans Are the Real Monsters.
- Zeke and Eren are half-brothers.
- Grisha's first wife, Dina, was forcibly transformed into the Smiling Titan, making Dina indirectly responsible for the deaths of Carla and Hannes.
- The "Coordinate" ability can be temporarily activated by a non-Fritz carrier without the First King's will impeding the user so long as they come into physical contact with an actual member of the Fritz bloodline who carries the Titan's Power themselves.
