|If Eren dies, Paradis will sink under a sea of blood!! The entire world will take vengeance on us! Your parents, your siblings, your children, they'll all be slaughtered!! Devote your hearts!!|
|— Floch rallies the Yeagerists in the battle at the harbor|
Floch Forster (フロック・フォルスター Furokku Forusutā?) was a former recruit (新兵 Shinpei?) of the Survey Corps. He joined the regiment before the return to Shiganshina District, where he was assigned to Squad Klaus. Other than Hange Zoë and Squad Levi, he was the only survivor of the battle. After discovering the truth, Floch developed a hatred for humanity outside the Walls. He was one of the Yeagerists becoming de-facto leader for the faction, he also believed Eren was the only one who can save the "New Eldian Empire" (新生エルディア帝国 Shinsei Erudia Teikoku?).
Floch appeared to be of medium height with short, tousled blond hair. During the return to Shiganshina mission, he wore the standard Survey Corps uniform and cloak. For casual clothes he wore a white button down shirt with dark pants.
Four years after the recovery mission, Floch's hair appeared with thick bangs which were swept to the right side, while keeping it shorter at the bottom. He had not grown much in height but still stood in a similar structure to his peers. During the night raid in Marley, he wore a new black Survey Corps uniform with anti-personnel vertical maneuvering equipment.
Floch was, by his own admission, a coward. Part of Floch's cowardice seemed to stem from a belief that his death should not be "meaningless," as he expressed during the Battle of Shiganshina District. Despite this, Floch had proved himself to be capable of acting courageously. He was willing to participate in Erwin Smith's suicide charge against the Beast Titan, despite his fear, and was willing to stand up to his fellow soldiers when they suggested allowing Erwin to die in favor of saving the life of Armin Arlert, even going so far as to risk being attacked by Mikasa Ackerman to keep her from taking the Titan injection from Levi.
One of Floch's most evident personality trait was his respect for Erwin Smith. He argued passionately for Erwin to receive the life-saving Titan serum, believing that only Erwin was capable of making the choices necessary to guarantee victory for humanity. He openly criticized the choice to save Armin over Erwin, and claimed that the choice was a result of those involved allowing their emotions to cloud their judgment.
Floch was also very honest with others, to the point of being insensitive. He admitted to Hitch that Marlowe must have regretted entering the Survey Corps in his final moments, and informed Armin that most Military personnel who had read the Corps' report from the Shiganshina battle agreed that Armin's survival was a mistake. It was possible that Floch's value of the truth stems from his experiences in Shiganshina, as he insisted that any future recruits be informed of what they will be signing up for, so that "cowards" like him will know not to join.
He believed that those who cannot give up something important to them for the greater good and refuse to listen to reason are childish. By that virtue, he thought of those who knew when to back off and restrain themselves from acting on their emotions as "adults." This is evident when he criticized Eren and Levi on their decision to save Armin instead of Erwin, while praising Mikasa, who though acted on impulse at the start, reigned herself in eventually and made the logical choice.
Four years after reclaiming Wall Maria, Floch adopted a more vindictive attitude towards humans outside the Wall; once joining the Yeagerists, Floch became even more open to using violence against anyone who is not an Eldian or resisted the efforts made by Eren, whether they were Marleyans or even his allies in the Anti-Marleyan Volunteers. Floch was open to conducting scorched earth tactics and was not concerned with collateral damage; he did not hesitate in burning entire city blocks in Liberio to the ground, simply to deny resources to the enemy with no thought of the casualties that would result from it. He also pointed out Eren's willingness to act as a demon by killing civilians and children as an example of their comrades’ willingness to take on the enemy ruthlessly.
During the feast before the expedition to Shiganshina District, Floch rhetorically asks Jean Kirstein if 104th recruits and former Garrison members such as himself and his friends are that unreliable. When Jean asks why he and his friends joined the Survey Corps, Floch says the increased propaganda for the Survey Corps after the uprising is what drew them in. He notes how much the 104th soldiers have changed since they had graduated.
During the operation to retake Shiganshina District Floch and the rest of the recruits enter Shiganshina on foot while the rest of the soldiers use their vertical maneuvering equipment to make their way to the top of the Wall. They are ambushed by the Beast Titan, who appears with an army of Titans and throws a boulder into the side of Wall Maria, causing a collapse that blocks the Survey Corps' entrance to Shiganshina, leaving Floch and the other soldiers unable to enter with their horses. Floch and his squad mates are left in charge of the corps's horses, and are ordered to defend them from any approaching Titans.
The Beast Titan begins to target his throws at the soldiers themselves, and Levi orders the recruits to take the horses closer to the Wall, where they can use buildings for cover. Floch begins to panic and Levi has to force him along to the base of the Wall. Marlowe scolds him for letting some of their horses run away in the attack, but Floch hysterically retorts that there is no point to watching the horses since the will all soon die. Recalling the ceremony where he decided to join the Survey Corps, Floch laments that he is going to die a meaningless death rather than bravely sacrifice himself for humanity.
When Erwin Smith gives his plan of a suicide charge against the Beast Titan to the recruits, Floch protests that they have no reason to participate in the charge since they will die either way. Despite his protests, Floch and his comrades are won over by Erwin's urging that they fight for the good of humanity so that the living can give meaning to their deaths. During the charge Floch is knocked off of his horse, but miraculously manages to survive. Shocked by his survival, Floch begins to wander the battlefield searching for anyone else who may have survived.
After finding Erwin wounded and bleeding on the battlefield, Floch treats the Commander's wounds as best he can before pursuing Captain Levi. As Levi prepares to give Eren Yeager the Titan injection needed to heal Armin Arlert, he arrives with Erwin hanging unconscious on his back. While the others begin to argue over who should receive the serum, Floch gives his opinion that Erwin should be the one to receive the serum as only a "demon" like Erwin can overcome the Titans. Eren tries to dissuade Levi from giving Erwin the serum, but Floch forcibly restrains him to stop him from interfering. Levi orders that he be left alone to inject Erwin, and Floch forcibly moves Eren to another house rooftop. After Armin is given the serum instead of Erwin, Floch is left dismayed and asks Levi why he chose Armin over Erwin.
As the remaining members of the Survey Corps prepare for a ceremony in their honor, they are approached by Hitch, who has come to watch the ceremony. Jean assures her that Marlowe acted bravely on their mission, and asks Floch to recount the events to her. Although Floch praises Marlowe for staying calm and encouraging his fellow recruits, he admits that Marlowe likely regretted his actions in his final moments. As Hitch leaves, an appalled Jean demands to know why Floch said such a thing to Hitch, and Floch tells him that someone should be honest about what happened. Armin admits that he knows Floch wanted Erwin to live, and Floch claims that everyone who has read the Corps' report believes Erwin should have lived. Eren tries to defend Armin, but Floch accuses him of acting childishly and allowing his personal feelings to keep him from making a rational choice. Jean and Connie intervene before things can escalate further, but Floch reprimands them as well, pointing out that they made no effort to stop Eren and Mikasa. Floch closes by demanding that they inform any future recruits of what they are truly signing up for, so that no more cowards like him join.
With the arrival of the Anti-Marleyan Volunteers, Floch is among those assigned to guard their leader Yelena. At the time there was a ceremony in Trost District, which was held in proximity to where Eren Yeager was staying.
Floch brings Yelena and Eren in contact so she could explain Zeke's true motives to euthanize the Eldian race. Sometime after the meeting with Yelena, Eren meets with Floch privately and states that he is going to follow Zeke in appearance only, asking him to do the same. Floch questions Eren about his true intention and Eren reveals that he will use the Founding Titan's power to bring ruin to the world. Floch agrees with Eren and begins gathering allies, forming a secret faction which would later be known as the "Yeagerists."
Approximately nine months later, Floch joins the Survey Corps at the Raid on Liberio where he sets explosives to destroy buildings around the internment zone. Jean yells at him to minimize civilian casualties, but Floch is unrepentant; he tells Jean of all of the people inside the Walls who were killed by the people outside of it. When Jean argues with him, Floch points to Eren and reminds Jean that Eren told them to fight rather than wait within the Walls for death to find them, declaring that Eren is the devil that they need. Some time after, Floch is forced to take cover from the Beast Titan's bombardment.
As the Survey Corps makes its retreat from Liberio, Floch leads the surviving soldiers in a celebration of their overwhelming victory against Marley. As they are celebrating, two children board the Corps' airship, and open fire, killing Sasha Blouse. In response, Floch and his fellow soldiers attack the children, savagely apprehending and disarming them. Floch asks Jean if he should throw them out of the airship, but is denied.
Unhappy with Eren's arrest following their return to Paradis, Floch and several other Survey Corps recruits leak news of Eren's confinement to the public, which puts pressure on Hange to release him. They are quickly discovered, and are called before Hange to explain themselves. Floch argues that Eren was justified in his actions, and that his actions have saved the lives of the citizens of Paradis. Hange points out that Eren's actions have only demonized them to the rest of the world, but Floch insists that they have nothing to worry about as long as Eren has the power of the Founding Titan. Rather than freeing Eren, Hange concludes the hearing by arresting Floch and his compatriots.
Floch and his companions are quickly freed by other members of the military who have sided with Eren, and the group makes a plan to meet up with Eren outside of the city. After Eren escapes his cell and arrives, Floch informs him of their numbers along with their involvement in Zackly's assassination. Floch claims only Eren can save the Eldian Empire and Eren tells the group he will locate Zeke.
After being informed of Hange's location by a sympathetic employee, Floch joins the other Yeagerists in raiding a restaurant. The faction threatens Hange and their subordinates with firearms, and Floch demands that they take them to Zeke's location. On Hange's query, he reveals to them that Eren refuses to negotiate with the military. Hange tries to reason with Floch, arguing that they do not have time to be infighting while Zeke is making his own moves, but their words fall on deaf ears and Floch orders that they be restrained. Hange deduces that Floch was aware of the spinal fluid scheme but Floch refuses to give an answer, only ordering Hange to remain quiet. When the captives are directed out, Floch taps on a door to inform Eren that they are leaving.
Arriving in Shiganshina, Floch immediately leads the Yeagerists to the division of the Training Corps operating out of the District. He and the Yeagerists inform instructor Keith Shadis and the recruits that the Yeagerists will now be operating out of the Training Corps's base, shooting off a warning shot when Keith attempts to resist. Floch invites all of the assembled recruits to join the Yeagerists and abandon their old customs from before they learned of the outside world. As recruits begin to join him, Floch informs them that they will have to prove their loyalty by beating Keith, and that anyone who does not will be thrown in jail. After the recruits have finished beating Keith, Floch orders Hange to take him to Zeke.
Floch and the Yeagerists with him learn that Zeke is in the custody of Levi and thirty members of the Survey Corps still loyal to the military. En route to their location, Floch hears a sound resembling thunder near the edge of the forest. They go to investigate and find a completely destroyed wagon, along with an injured soldier lying on the bank of a river. Floch expresses his initial worry about Levi being a problem, but is pleased to see he will not be a concern due to his injuries; after hearing Hange claim that Levi is dead, Floch is not fully convinced and orders Hange to move so he can check for a pulse. However, before he can, he and the other soldiers are suddenly distracted by the sight of Zeke emerging from inside a decomposing Titan. This gives Hange the opportunity to flee with Levi's body, catching Floch off guard while other Yeagerists leave to pursue them. Floch then tries to get Zeke to explain what happened but Zeke brushes him off claiming that they need to move on.
Floch and his soldiers arrive with Zeke at Shiganshina to find it under attack by Marley's forces. While Zeke pummels Marley's Titans with rocks from atop the Wall, Floch takes his group to kill the Cart Titan and keep it from using its artillery to hurt Zeke. They seemingly manage to take the Titan down but are caught off guard when Marleyan soldiers appear from the Cart Titan's corpse and begin firing on them, forcing them to retreat.
Floch and his soldiers continue to attack the Cart Titan, but are quickly repelled, with everyone except for Floch being killed. As Floch confronts the worsening situation, Eren makes contact with Zeke and starts the Rumbling as Floch watches the Wall begin to crumble from beneath him.
Despite sustaining a head injury, Floch survives the collapse of the Walls. After all of Zeke's Pure Titans are killed, he meets with the survivors at the headquarters. He talks with Jean, expressing that he could not die during the moment of the Eldian Empire's return. Floch then points his gun at Yelena and demands her to gather the Anti-Marleyan Volunteers so they can be detained.
One of the Volunteers tries resisting and Floch wounds the man by shooting him in the hand. Floch informs the Volunteers that he has known about Eren's plan to unlock the Founding Titan for 10 months. He acknowledges that the Volunteers' respective homelands will indeed be destroyed by Eren's plan and offers to grant them status as honorary Eldians in the new empire Eren will create if they agree to cooperate. The injured Volunteer continues to belittle Floch, who responds by nonchalantly executing him.
As the Volunteers are led away, Floch claims to Jean and Mikasa that, as Eren's representative, he is trying to wipe out any resentment in Paradis. In an attempt to gain Jean's support, Floch makes an appeal to Jean's old desire to live a comfortable life as an MP. Mikasa demands to know what happened to Levi and Hange and Floch claims that Zeke killed them.
In the following days, Onyankopon and Yelena continue to resist Floch's invitation to join the Yeagerists as honorary Eldians so he decides to have them publicly executed. Floch and Jean bring the two Volunteers before the Yeagerists and Floch announces their execution, explaining that Yelena conspired with Zeke to destroy the Eldians and that Onyankopon had chosen death over joining Yeagerists. Jean fires four shots at Onyankopon and misses all of them, and to Floch's shock, the Cart Titan suddenly attacks, eating Jean, Onyankopon and Yelena.
Floch takes a group of Yeagerists to Paradis' harbor to confront the Azumabito clan and force their mechanics to cooperate with them. After executing three of Kiyomi's companions, he gloats about Eren's impending success and cheerfully reminds them that Hizuru will also be wiped out. He attempts to coerce her into agreeing to help the Yeagerists but Kiyomi only reminds him that the Eldians will keep killing each other even after the outside world is destroyed. Floch disregards her warning and threatens to kill her, admitting that he is willing to sacrifice Paradis' technological advancement to eliminate potential enemies.
He is interrupted by Connie and Armin arriving at the harbor, explaining that they need the Azumabito mechanics to pilot their airship so that they can pursue the Cart Titan. Suspecting that the two are lying, Floch decides to execute the Azumabito mechanics to keep them from posing a threat in the future. However, he is caught off guard and disarmed by Kiyomi. Before Floch's comrades can help him, Mikasa bursts into the building and incapacitates them as well. With no one to help, Floch flees the building and announces to the rest of the Yeagerists that they are under attack.
As the Yeagerists attack, Floch becomes uneasy that Mikasa and the Azumabito have fled to the basement. As the Armored and Female Titans transform, Floch realizes that they have been led into a trap and turns his attention to fighting off the Titans.
During the battle, the Azumabitos attempt to reach the boat and Floch, realizing that they intend to take the boat, frantically orders his soldiers to target them. When they fail to kill the Azumabitos, Floch orders his troops to instead target the flying boat to ensure that it cannot be used to reach Eren.
When the Cart Titan appears, Floch tries to target her himself but is caught off guard by the emergence of the Jaw Titan. While his soldiers are killed, Floch manages to escape the Jaw Titan and targets the boat, attempting to sink it with a Thunder Spear while saying that he will be the savior of Eldia. However, as he is firing, he is shot by Gabi Braun, throwing off his aim and causing him to plummet, injured, into the ocean.
Despite his injuries, Floch manages to attach his maneuvering gear's anchors to the boat and follows the group across the ocean to Odiha. Badly injured, Floch is able to drag himself into the hangar where the Azumabito mechanics are preparing the flying boat for takeoff and begins firing on them. He manages to hit the boat's fuel tank, but Mikasa quickly fires one of her anchors into his throat. As the mechanics attempt to fix the boat, Floch uses his last breath to beg Hange and Jean to stop pursuing Eren, citing that his rumbling, though immoral, was Paradis' only hope for survival.
- Eren Yeager - Floch used to consider Eren as an immature and stubborn person due to the latter's behavior at the Battle of Shiganshina. However, after seeing his willingness to do what needed to be done to secure Eldia's freedom, Floch began to change his views on Eren and regarded him as a savior and the one who should rule Eldia. In his last moments Floch begged Jean and Hange not to stop Eren's Rumbling, calling him a devil yet the only hope for Eldia's survival, emphasizing how much trust and faith Floch had in Eren.
- Jean Kirstein - Floch viewed Jean as a capable soldier as he joined the Survey Corps, though he was concerned as to the events that hardened Jean and other members of the 104th. Through their interactions before the timeskip, it could be seen that the two were on friendly terms. During the Raid on Liberio, the two had a disagreement after Floch disobeyed Jean's orders, showcasing somewhat of a lack of respect. After Floch abandoned the military, the two were seen to be on hostile terms. Jean was later a witness to Floch's arrest of the Anti-Marleyan Volunteers, yelling at Floch to stop and appearing in disbelief after hearing Floch's words. When Floch killed a volunteer, Jean was left shocked, and Floch told Jean that he was free, and should go back to being how he used to be, with Floch mocking Jean's former self, calling him "bastard." Floch did, however, refer to Jean as a hero, showcasing a potential, if discarded, respect.
- Erwin Smith - Floch held the former leader of the Survey Corps in high regards, and believed Erwin's ruthlessness made him capable of leading humanity towards salvation. He staunchly advocated that Erwin be saved during the final stages of the Battle of Shiganshina District instead of Armin.
- Armin Arlert - Floch developed a sense of dislike towards Armin when the latter was chosen to be given the Titan serum instead of Erwin, whom he believed to be the one who could save humanity.
- Hange Zoë - At first, Floch viewed Hange as a competent successor to lead the Survey Corps. However, he would later turn against Hange and see them as an enemy along with the other members of the military.
- Keith Shadis - Despite claiming he harbored no ill will towards Keith, Floch had a low opinion of his former training instructor. Viewing him as a relic of the past, Floch was perfectly willing to shoot Keith and ordered the new recruits to beat him as a means to prove their loyalty.
- Zeke Yeager - As Eren's older half brother, Floch feigned utmost respect for Zeke; always addressing Zeke as "Sir." In actuality, Floch held Zeke in contempt, and only pretended to follow him because of Eren's orders.
- Marlowe Freudenberg - Floch respected Marlowe’s bravery and leadership qualities. They were both part of Squad Klaus during the Battle of Shiganshina District, tasked with safeguarding the horses. While recounting Marlowe's bravery to Hitch after the battle, Floch praised him as an "amazing guy", but admitted that in his final moments he must have wished that he had never come.
- Floch ranked thirty-third in the Third Character Popularity Poll.
- Hajime Isayama has claimed that he did not initially plan for Floch to become a prominent character or for any character to fill a role such as his. However, he came to feel that Floch was necessary to act as a voice of opposition against the main characters.