This is a summary of the main plot and subplots of the manga series Attack on Titan, which follows the story of humans living in a world where they are threatened by giant creatures called Titans. The summary covers the events from the beginning of the series until chapter 123, which was published in December 2019.
The summary is:
- The Eldians are a race of people who can turn into Titans by inheriting one of the nine Titan powers that originated from Ymir Fritz, the first Titan. The Eldians built an empire that oppressed other nations, but eventually collapsed due to internal conflicts and a revolution led by King Fritz, who took most of his people to an island called Paradis and erected three concentric walls to protect them. He also erased their memories and vowed to renounce war, using the power of the Founding Titan that he inherited from Ymir.
- The Marleyans are a nation that fought against the Eldians and gained control of seven of the nine Titan powers. They used the Titans as weapons to expand their colonial empire, but also discriminated and persecuted the Eldians who remained on the mainland. They also planned to invade Paradis and reclaim the Founding Titan and its resources.
- Eren Yeager is the main protagonist, who lives in Shiganshina, a town within the outermost wall of Paradis. He witnesses his mother being eaten by a Titan during a surprise attack by the Colossal Titan and the Armored Titan, who breach the wall and allow other Titans to enter. He vows to kill all the Titans and joins the Survey Corps, a military branch that ventures outside the wall to fight and study the Titans.
- Eren discovers that he has the power to turn into a Titan after being injured during a battle. He also learns that his father Grisha, who disappeared after the attack, was an Eldian doctor from Marley who joined a rebel group called the Restorationists. Grisha inherited the Attack Titan from a fellow rebel named Kruger, and later stole the Founding Titan from the royal family of Paradis by eating its holder, Frieda Reiss. He then passed both powers to Eren by injecting him with Titan serum and letting him eat him.
- Eren and his friends face various enemies and mysteries, such as Annie Leonhart, who is revealed to be the Female Titan and a Marleyan spy; Reiner Braun and Bertolt Hoover, who are Eren's comrades but also the Armored Titan and the Colossal Titan respectively; Zeke Yeager, who is Eren's half-brother and the Beast Titan; Ymir, who is a former cult leader and the Jaw Titan; Historia Reiss, who is the true heir of the royal family and has the power to activate the Founding Titan with her blood; and Willy Tybur, who is the leader of a noble family that holds the War Hammer Titan and secretly controls Marley.
- Eren and his allies manage to retake Wall Maria and reach the basement where Grisha left his journals, which reveal the truth about the world and the history of the Titans. They also learn that they have only 13 years to live after inheriting a Titan power, due to a curse that Ymir suffered. Eren decides to use his powers to free his people from their enemies, even if it means defying his superiors and risking a global war.
- Eren infiltrates Marley and launches an attack during a festival where Willy declares war on Paradis. He kills Willy and eats his sister Lara, who was the War Hammer Titan. He also fights against Reiner, who inherited the Armored Titan from Marcel Galliard; Porco Galliard, who inherited the Jaw Titan from Ymir; Pieck Finger, who is the Cart Titan; and Zeke, who betrayed Marley and joined forces with Eren. Eren escapes with Zeke and some of his friends, while others are captured or killed.
- Eren returns to Paradis with Zeke, who claims to have a plan to end the cycle of hatred and violence by using the Founding Titan's power to sterilize all Eldians and prevent them from having children. However, Eren secretly opposes this plan and has another one in mind: to use the Founding Titan's power to unleash all the Titans within the walls and trample all life outside Paradis, in an event called "the Rumbling".
- Eren's plan causes a rift among his friends and allies, some of whom support him and some of whom oppose him. He also faces resistance from Marley and other nations, who form an alliance to stop him. Eren declares that he will not stop until he destroys all his enemies and frees his people from their fate.
Here are the key facts extracted from the text:
1. 1820 years ago, the first generation used giants' power to build the Eldia Empire.
2. The Empire was founded with the help of nine giants, each with a 13-year tenure.
3. If a giant's power is not inherited within this period, it is randomly passed on to a new Eldian offspring.
4. The Eldians conquered the Marley Empire and became dominant in the new world.
5. They forced other nations to reproduce and committed numerous atrocities.
6. 80 years ago, Fritz 145 led a revolution with the Warhammer giants.
7. They created a puppet hero named Cross to weaken the Eldia Empire.
8. The Eldia Empire eventually collapsed due to internal strife.
9. King Fritz retreated to Paradis Island, creating a peaceful haven.
10. The Marley government used the remaining Eldians as tools and scapegoats.
11. A revolutionary army formed among the oppressed Eldians on the mainland.
12. Xiaoqing infiltrated the Ministry of National Defense through deception.
13. Grisha indoctrinated his son with Eldian and Marleyan ideologies.
14. Grisha later married and had a second son named Zeke.
15. The Malay government planned to reclaim full control over all giants.
16. Lennar and others embarked on a mission to save humanity 13 years ago.
17. Grisha used his powers to defeat Frieda Reiss and inherit her abilities.
18. Alan Yeager inherited Grisha's powers after his death.
These are the main factual points from the provided text without any opinions or additional commentary.