Founding Titan

The Founding Titan (始祖の巨人 Shiso no Kyojin?, also translated as Progenitor Titan) is one of the Nine Titans, and the first of all Titans. Its Scream (叫び Sakebi?) can create and control other Titans, and modify the memories and body compositions of the Subjects of Ymir, but this power can only be used by the royal family under normal circumstances. It is currently in the possession of Eren Yeager.

According to Marley's Titan Biology Research Society, the Founding Titan is the point where the paths that connect all Subjects of Ymir and Titans cross. Because of this, those who hail from Marley sometimes call it the "Coordinate" (座標 Zahyō?).

Abilities
The Founding Titan has several abilities that are activated by screaming. The inheritor of the Founding Titan does not have to transform in order to use these abilities, and human screams would suffice. Furthermore, the screams do not have to be loud or even "screams": Frieda Reiss used the memory alteration ability by casually talking, although her target was only Historia, who was right in front of her.

Titan creation
The Founding Titan can transform Subjects of Ymir into Titans and can even make them as massive as the Colossus Titan. Karl Fritz used this ability to create the thousands of Colossus Titans that make up the Walls.

Zeke Yeager's Beast Titan can also transform Subjects of Ymir into Titans by screaming after injecting those he wishes to transform with its spinal fluid. It is said that Zeke's Beast Titan has abilities similar to the Founding Titan; therefore, it can be assumed that the method for the Founding Titan is similar, if not identical.

Titan control
By screaming, the Founding Titan grants its user the ability to control Titans at will and make them follow virtually any order. This was demonstrated by Eren Yeager, who unintentionally commanded nearby Pure Titans to eat Dina Fritz's Titan and attack the Armored Titan. It appears to be only effective on Pure Titans, although those with the power of the Titans can still feel its influence. It was also used by Karl Fritz to build the Walls, commanding many Colossus Titans to harden their bodies and confine themselves into the resulting structures. In ancient times, Eldia used to use this ability to command an army of Titans for war; however, once set loose, these Titans became indiscriminate weapons of mass destruction that would slaughter Eldia's enemies. This ability has no known range, although Karl Fritz used it to command Colossus Titans that span across a large portion of Paradis Island. Rod Reiss claimed the power has the capacity to wipe out all the Titans, if used to its full potential.

Memory manipulation
The Founding Titan is able to modify the minds and memories of the Subjects of Ymir, even entire populations at once. This ability is related to the Titan control ability: As noted by Erwin Smith, Titans are simply transformed humans (specifically, the Subjects of Ymir); therefore, the screams that control the minds of the former should be able to affect the latter as well. It was used by Karl Fritz to make the Subjects of Ymir inside the Walls forget the history of the world before the Walls' installation. It was also used by Frieda Reiss to remove Historia's memories of her visits. These memories, however, appear to be accessible in dreams, as Historia would sometimes be able to dream about her encounters with Frieda, although she would forget about them once she awoke. Members of the Ackerman bloodline and anyone who is not a Subject of Ymir are unaffected by this ability.

Anatomical manipulation
The Founding Titan can change the body composition of any Subject of Ymir. An Eldian king from 600 years ago once used this power to make the Subjects of Ymir immune to a rampant epidemic. Zeke Yeager planned on using this ability to make all Subjects of Ymir sterile, so that the world can be rid of Titans once and for all. After thwarting Zeke's plan, Eren uses this ability on a smaller scale, to re-attach his severed head to his body (after Gabi Braun shoots it off with an Anti-Titan rifle), saving his body from completely dying.

Additionally, the Founding Titan is known to have a height of around 13 m. However, it is possible that this size restriction is not as definite as it is with the other eight members of the Nine Titans as can be seen when Eren Yeager is able to transform into a Titan body many magnitudes of size larger than even the Wall Titans after receiving full use of the Founding Titan's power from Ymir Fritz.

Telepathic communication
The Founding Titan can telepathically connect with all of the Subjects of Ymir by way of the paths they are connected to. Eren used this ability to communicate with every Subject of Ymir when announcing his rumbling of the world.

Royal Bloodline Necessity
Only those with royal blood—the Fritz or Reiss royal families—are able to use the true power of the Founding Titan. However, if the Founding Titan is inherited by someone outside of the royal family, the power can still be used if the inheritor is in physical contact with a Titan with royal blood. This is demonstrated when Eren Yeager temporarily used the Founder's power after striking the hand of Dina Fritz's Pure Titan. It is implied by Zeke Yeager that it does not matter if the Titan of royal blood is a Pure Titan or one of the Nine Titans, such as the Beast Titan.

If the inheritor touches a human of royal blood, although the full power of the Founding Titan is still locked, some snippets of the previous inheritors' memories can be realized. The touch of Historia Reiss and her father Rod occasionally resurfaced the memories of Grisha Yeager. However, these memories are erratic and do not always come.

If a person of royal blood possesses one of the other eight of the Nine Titans instead of being a Pure Titan and that person comes into contact with an inheritor of the Founding Titan that lacks royal blood (which is the case for Zeke Yeager, a descendant of the Fritz family that stayed on the continental mainland, thus not descended from Karl Fritz and his half-brother Eren who lacks royal blood) then the royal-blooded person can use the Founding Titan's true potential instead of the actual inheritor. This is due to the fact that the Founding Titan's true capabilities are used through commanding the soul of Ymir Fritz, the first of the Titans, whose master-slave mentality was kept intact after her death, and as the First Fritz King was her master as well as the father of her children, she remained in submission for millennia until Eren Yeager freed her and she complied with his plea to "end the world", signifying that Ymir is no longer bound in servitude to her descendants, likely meaning that the Founding Titan's blood necessity is now rendered null and void.

Vow Of Renouncing War
Despite having the ability to control the Titans, no Founding Titan of royal blood after the Great Titan War expressed any desire to get rid of the Titans outside the Walls, even if the inheritor had expressed that desire previously. This is because these Founding Titans inherited the ideology of Karl Fritz along with his memories. Even before he inherited the Founding Titan, he believed that the Eldian Empire committed too many atrocities towards the world, and the Eldians should be locked up inside his "paradise" within the Walls, segregated from the rest of the world; the Titans sent by Marley help prevent the Eldians from leaving the Walls, fulfilling this goal. He made a vow renouncing war (不戦の契り Fusen no chigiri?) to stop Eldia from ever using the Founding Titan again to devastate the world.

The vow "possesses" the King's successors and greatly changes their personality: They become compassionate, desire to create a "paradise" inside the Walls, and preach about peace and love among mankind. However, Frieda Reiss called the people inside the Walls "sinners," and used to suffer from fits of madness and depression. Frieda, who is normally kind to Historia Reiss, once became furious at her for attempting to go over the fence surrounding her farm (paralleling the Eldians trying to leave the Walls).

The vow also prevents them from using the Founding Titan's true power for combat, even for self-defense. Karl Fritz knew that the paradise he made for the Eldians is only temporary, and that one day, Marley or the other nations of the world will invade. He accepted any form of retribution the world decides for the Eldians, even extermination, and his vow forces any inheritor of royal blood to comply. No matter what, they will not fight back against any attack against the Eldians, and if the Eldians are slaughtered, so be it.

Circumventing the vow
The vow only applies to members of the royal family; therefore, the vow can be bypassed if the inheritor of the Founding Titan is not related to the royal family and is in physical contact with someone of royal blood.

Despite being a descendant of the royal family, Zeke Yeager claims that he was able to learn how to nullify the vow during his time spent within the Founding Titan's realm which he entered without being tainted by the first king's ideology unlike the previous kings of the Walls.

History
Around 2,000 years ago, Ymir Fritz's village was attacked and enslaved by the Eldians, who then cut out their tongues. One day after a pig was released, the tribe's ruler, Fritz, called all of the slaves and asked for the culprit. The slaves all began to point at Ymir, who was then "freed" only to be hunted by dogs and men.

Wounded and desperate, Ymir took shelter in a nearby tree, but as soon as she stepped in, she slipped and fell into an underground body of water. There, she came into contact with a mysterious spine-like creature which attached to her back and triggered the first Titan transformation.

With her newfound power, Ymir returned to serve Fritz and used her Titan to cultivate land, build bridges, and amass wealth for the Eldians. Under his command, she also destroyed the forces of Eldia's rival, Marley. To "reward" Ymir for her service, Fritz took her as his concubine giving her his name and, together the two had three children: Maria, Rose, and Sheena.

After serving the king for 13 years, Ymir died while thwarting an assassination attempt on his life. After her death, Ymir found herself inside a mysterious land, meanwhile the king forced his daughters to eat Ymir's corpse in an attempt to preserve the power of the Titans. He commanded the daughters to continue to reproduce and cannibalize each other so that Ymir's blood does not run out and Eldia could rule forever with its Titans. Ymir's powers became the Nine Titans and she continued to serve her descendants, building them Titans whenever they invoked the power of the Titans.

After these seventeen centuries, the Founding Titan was inherited by Karl Fritz, the 145th King. King Fritz chose to abandon the conflicts of Eldia and relocated the capital of Eldia to Paradis Island where he used the Founding Titan to create many Colossus Titans in the building of three Walls: Maria, Rose, and Sheena. In the absence of the Founding Titan, the Great Titan War continued. Over the course of the war, Eldia lost all its territory on the continental mainland to Marley and its people fled overseas to Paradis Island where they entered into the Walls. Some time after the people were gathered within the Walls, King Fritz used the Founding Titan to erase the memories of the outside world from most of the population's minds, leading them to believe they were the last remnants of humanity in a world overrun by the Titans.

Upon the closing of the gates of Wall Maria, King Fritz announced to his relatives who chose to remain across the sea that a pact had been made with the Founding Titan. In order to secure peace for Eldia while simultaneously arranging for the nation's eventual destruction, King Fritz ensured that all successors after him would be overcome by his will if they chose to use the Founding Titan for Eldia's sake. Some time afterward, the King passed his power over to his descendants in the royal family, now known as the Reiss family.

For generations, the Reiss family passed the Founding Titan down from successor to successor. Eventually, the Founding Titan was inherited by Uri Reiss from his father. Early in his life with the Founder, Uri protected himself from Kenny Ackerman using his Titan, and he would later become a close friend of his would-be assassin.

Sometime later, in the year 842, Uri Reiss passed on the Founding Titan to his niece Frieda Reiss, daughter of his older brother Rod Reiss. Frieda presumably made little use of the Founding Titan for the next three years, though on occasion she visited her half-sister Historia Reiss and used the Founding Titan to erase her memories of each visit. When three years had passed, the fall of Wall Maria began. After hearing of the attack on Shiganshina District, the Reiss family gathered in the underground cavern beneath the chapel where the Founding Titan had been passed on for generations. While in the cavern, they were visited by Grisha Yeager, who had been tasked by Eren Kruger with taking the Founding Titan thirteen years ago. Grisha identified himself as an Eldian and a Subject of Ymir and begged for Frieda to use the Founding Titan to save the people of the Walls, but his pleas went unanswered. Seeing no choice but to fulfill his promise to Kruger, Grisha transformed into the Attack Titan and fought with Frieda's Founding Titan. Due to her inexperience, Frieda was quickly overpowered and Grisha stole her power, killing Frieda before turning his attention to the Reiss family and wiping out their line, except for Rod who escaped with his life.

Grisha returned to Wall Rose shortly afterward and searched for his family. He found his son Eren and adopted daughter Mikasa, but learned that his wife Carla had been killed. Grisha entrusted Kruger's mission to Eren, leading him into the woods alone and injecting him with a Titan serum. Eren would have no memory of the event for the next five years, and as a Pure Titan, he consumed his father, inheriting both the Attack Titan and the Founding Titan.

Clash of the Titans arc Edit
For five years, the power of the Founding Titan remains unused until the year 850. Believing that Eren Yeager is the current inheritor of the Founding Titan, the "Coordinate" sought after by Marley, the Warriors capture him with the intent of taking him to their hometown. At this time, the Survey Corps comes to his rescue and a chase ensues. When Eren is freed from the Warriors' grasp, he comes into contact with the Dina Fritz's Titan during the Wall Rose invasion, his father's first wife and a descendant of royalty. In a moment of rage, he punches the hand of Dina's Titan, contacting her royal matter, and the power of the Founding Titan comes forth in that moment in the presence of her royalty. Following Eren's will, all the Titans nearby attack Dina's Titan, tearing it to pieces and allowing for the Survey Corps to escape. When Reiner Braun attempts to pursue Eren, he threatens him and the other Warriors to stay away, and the Founding Titan reaches out to the Titans nearby, causing them to chase after Reiner's Armored Titan.

The Uprising arc
Eren's ability to control the Titans becomes a key mystery for the Survey Corps. Over a week after the Wall Rose crisis, the Founding Titan begins to leak memories of its previous inheritors into Eren's mind, where he sees visions of Frieda Reiss before forgetting the memories. Around the same time, Historia Reiss begins seeing memories of Frieda's visits in her dreams, though she does not remember them when she awakens.

Sometime later, Eren and Historia are captured by Rod Reiss, who desires to feed Eren to a Titan Historia in order to return the Founding Titan to the Reiss family. In the underground of the Reiss Chapel, Rod and Historia place hands on Eren's body, and their royal presence brings out the memories of his father, Grisha, taking the Founding Titan from Frieda five years before. Rod recalls the story of the event and explains the nature of the Founding Titan to Historia and how it influenced the monarchs of the Reiss family since the time of the First King. Historia nearly accepts the task, but refuses it in the end. In desperation, Rod ingests the Titan serum meant for Historia, becoming a Titan of gargantuan size. After escaping from the underground of the chapel, Eren attempts to use the power of the Founding Titan to stop Rod's Titan from advancing towards Orvud District, though he makes no progress and does not understand why.

Return to Shiganshina arc
Two months later, the Survey Corps reclaim Shiganshina District. They come to the Yeager family's basement where Grisha had kept his secrets for Eren. In one of three journals hidden within the basement, they read Grisha's story of his childhood and when he learned the nature of the Founding Titan. In Grisha's past, he had joined a group of Eldian Restorationists who desired to take the Founding Titan from the king of the Walls in order to restore Eldia to glory. The organization failed and Grisha alone was given the task of taking the Founding Titan by Eren Kruger, an Eldian spy in the government of Marley.

When the military of the Walls gathers to discuss the discoveries from the basement, Eren thinks back to the time when the Founding Titan came forth in the presence of the Titan that ate his mother. Recalling his father's memories of his first wife, Dina, Eren realizes that Dina's Titan was responsible for the presence of the Founding Titan. However, Eren decides against revealing his discovery to the military, fearing that the idea of turning a royal into a Titan for Eren to come into contact with may put Historia Reiss's life at risk.

War for Paradis arc
After realizing that he can use the Founding Titan by coming into contact with Zeke, Eren decides to pretend to go along with his half-brother's plan to sterilize the Subjects of Ymir. After they make contact and enter the Founding Titan, Eren discovers that the Founder's power is used by commanding Ymir Fritz before he reveals his deception and learns that Zeke not only nullified the vow of renouncing war, but that he controls the power of the Founder, showing that if a person with royal blood possesses one of the Nine Titans, (instead of being a Pure Titan) they can use the Coordinate's full power instead of the actual holder.

After viewing their father's memories, Zeke learns of the Attack Titan's ability to see into the future and that a future inheritor can influence one in the past (which Eren uses to convince his father to slaughter the Reiss family, and steal the Founding Titan), Zeke initiates his plan and commands Ymir to sterilize all Subjects of Ymir. Following this, Eren breaks free from the chains Zeke crafted and rushes to stop Ymir.

Reaching Ymir, Eren embraces her and begs that she give him her strength so that he can end the world. However, he assures her that he is not going to force her to help him. He recognizes that she is neither a slave nor a deity, she is only a human being and she has the right to choose if she wants to remain in the Coordinate forever or help him end it all. As Zeke desperately tries to stop him, Eren asks Ymir if she was the one who led him to the Coordinate, musing that she has been waiting 2,000 years for him to arrive.

Eren uses the Founding Titan's powers to unleash all of the Wall Titans while creating a body for himself that is even larger than the Colossus Titans. He then uses the Founder's power to telepathically communicate with all of the Subjects of Ymir, informing them of his plans to destroy the world outside Paradis Island.