Battle of Trost District arc

Battle of Trost District Arc is the third story arc of the Shingeki no Kyojin series. Shortly after their graduation, the members of the 104th Trainees Squad are thrown into a fight against the Titans as the Colossal Titan appears at Trost District and breaks through the wall. During the battle, Eren learns of the mysterious power deep inside him.

Summary
The Colossal Titan, who hasn't been seen in five years, appears out of nowhere and Eren and his companions are attempting to counter his attack on the wall.

Using his Three Dimensional Maneuver Gear, Eren climbs the Colossal Titan's arm and goes for its head. Along the way, he notices that the Titan isn't attacking at random, but taking out cannons and aiming for vital spots on the wall. Going in for the kill, Eren heads for the weak spot on the nape of the neck. However, the Colossal Titan emits a burning steam that would blow Eren away if it were not for the line puncturing the Titan's back. Still at range of the nape, Eren sees his chance and attempts once more to slash it, but just like five years ago, the Colossal Titan disappears into thin air. Thomas asks if his attempt was successful, to Eren's dismayful reply.

Soon after, a member of the Garrison shows up and tells the trainees that the Colossal Titan contingency plan has already started. He then orders Eren to report to headquarters due to making contact with the Titan. Connie Springer wishes the advance team good luck. With the Survey Corps out on exploration, the Garrison are the only military presence available to repair the wall and prepare for an ambush. The city is once again in hysteria. The lack of soldiers puts the trainees in the sink or swim position of filling in the gaps.

Eren finds Armin, who quickly give him a run down of the dire situation. There is an eight meter high hole in the wall and the rock meant to fill it in hasn't even been excavated yet. With the hole there, the city will be abandoned and Wall Rose will be vulnerable. Briefly letting the fear get the better of him, Armin worries that the Titans could eradicate humanity at any time. Eren calms him and he is able to gather himself and continue his work.

The trainees are given their instructions. They will be divided into three groups, the front, middle and rear guard. The trainees are made aware of their commitment; fleeing in front of the enemy will be met with capital punishment and they are to give their live if necessary. As they are dismissed, Mikasa tells Eren to find her if things get confusing in battle. However, she is then assigned to the rear guard due to her superior physical abilities, making the request to Eren difficult. Angry, Eren tells Mikasa to stop trying to impose her own rules; he then apologizes for getting carried away. Distraught, Mikasa has one more request for Eren and that is not to get killed.

Eren thinks back to how little is known about the Titans. The information they do have is all thanks to the Survey Corps. What they do know, is that the Titans don't show interest in eating any creature other than humans and they've lived largely devoid of humans for 100 years; which suggests it isn't for nourishment. What stands out even more, is their vitality and ability to heal from seemingly devastating wounds. The only spot they can't regenerate from is at the nape of the neck; a blow which is best delivered using Three Dimensional Maneuver Gear.

Now on top of a roof in their assigned position, Eren and Armin, along with other trainees, prepare for the task ahead. Eren, encouraging Armin, says that they should be able to rise through the ranks of the Survey Corps quickly if they start practicing now. Not wanting to be outdone like the previous encounter, Thomas and other trainees suggest a Titan hunting contest and with that, they are on their way. Almost immediately, they run into Titans who have come through the hole in the wall. It seems that the front guard already have more than they can handle. As the group is moving along the rooftops, a Titan lunges for an attack. They scatter but unfortunately, Thomas isn't fast enough and gets caught. Eren and his squad watch in horror as his teammate gets swallowed whole.

Now in a rage, he rushes off to try and kill a Titan with its back turned; not noticing the Titan that is below him. The Titan jumps up and bites off Eren's leg below the knee. Watching Eren bleeding and stranded on a nearby rooftop, Armin goes blank. The remainder of the team attempt to kill the Titan below, with Nac Tius and Mylius Zeramuski being caught and Mina Carolina being knocked into a wall. Still in shock, Armin watches as his teammates are eaten before his eyes. A nearby Titan, taking advantage of the ensuing fray, grabs Armin and attempts to swallow him. Bleeding and half unconscious, Eren sees his friend in need and briefly remembers a childhood memory. Gathering all of his strength, he picks himself up and rushes to the aid of his friend. Inside the mouth of the Titan, Eren grabs Armin before he's swallowed and throws him outside. With Armin now safe, Eren attempts to escape. As they reach for each other, the Titan bites down and cuts off Erens arm, who is now trapped inside of its mouth. Armin watches in terror, as the the giant swallows Eren. In the distance, Mikasa is seen staring in the direction of her friends with an uneasy feeling.

Attempting to repair the damage from the Colossal Titan and deal with the Titans that have entered through the hole, the Stationary Guard and trainees are spread thin. Atop the wall, troops unleash a volley of cannon fire on the approaching Titans to no avail. On the ground, the vanguard has been eliminated.

Connie finds Armin still in shock from what has happened. As Connie is trying to get answers, they are joined by another trainee who wonders why they bothered to save Armin. This outrages Connie who lunges toward the trainee only to be stopped by Krista. She manages to diffuse the situation and and Armin gathers himself and joins the rear guard, while Connie and the others join the front.Distraught, Armin tries to make sense of the situation. He recalls Eren and Mikasa coming to his rescue while being bullied and wishes he could have had that kind of strength. Still on his way to the rear, he notices Hannah crouching over a bifurcated and obviously, lifeless Franz. In disbelief, she is attempting to reanimate him, to no avail. The sight is too much, causing him break down again; Armin is at his limit.

In another part of town, citizens are turning on each other in the confusion. A fight breaks out when a merchant's wares are too large to fit through the gate. Instead of stepping aside and letting citizens go first, he insists that the merchandise goes through as he says it's more valuable. A Titan is seen quickly closing in on the crowd. Just as it seems all hope is gone, Mikasa overtakes the Titan and makes short work of it. With her comrades giving their lives to protect them, she sees the goods blocking the gate and asks why the evacuation is taking so long. The merchant sharply replies that it is their jobs to do so. Reversing that line of thought against him, she counters that if their deaths save lives, then perhaps his would also. Briefly calling her bluff, he changes his mind when he sees she's serious. With the merchandise out of the way, the grateful refugees are now able to escape to safety. When a small girl turns and thanks Mikasa, it causes her to flash to her childhood.

In an isolated cabin, Mikasa's mother is seen bandaging Mikasa's arm and giving a brief explanation of the symbol of their clan. She tells Mikasa that one day, she will pass it down to her children which causes her to ask her mother where children come from. Trying to avoid the awkward question, her mother attempts to pass it off to her father, who then says to ask Dr. Yeager when he arrives. After a knock at their door, the scene changes to Dr. Yeager and Eren standing outside the door. Dr. Yeager is preparing to introduce his son to Mikasa and hopes they'll get along, as there aren't many children around the area. When no one answers the door, Dr. Yeager appears worried and lets himself in, calling to see if anyone is in the house. As the door opens, he sees the lifeless bodies of Mikasa's mother and father.

Finding the dead bodies of Mikasa's parents, Dr. Yeager instructs Eren to wait for him downstairs as he calls the police.

In an unknown location, Mikasa is shown tied up and laid out on the floor. Turning her over to get a good look at her face, her captors discuss the prospect of selling her in an underground market. Taking note of her "oriental" ethnicity, they imagine the price they could receive. Recalling the events, they remember Mikasa is only biracial because her father was a white man and only her mother was Oriental. One of the assailents reprimands the other for killing the mother, saying they could have gotten a higher price for her because she was the last pure blooded Oriental. The other defends himself by replying that he had no choice because she was resisting and he had to kill her. The missing chain of events that occurred before Eren and Dr. Yeager's arrival are then revealed.

Expecting the doctor, Mikasa's father opens the door when they hear someone knocking. Opening the door, one of the two men stabs him in the abdomen. Immediately grabbing the closest available weapon, Mikasa's mother lunges at the two men and tells Mikasa to "get out of here". Too frightened to move, she watches as her mother is struck with a hatchet and drops to her knees. With the parents dead, the men close in on Mikasa and threaten her not to give them any trouble. She wonders to herself where she could have gone if she had fled when her mother told her to.

Meanwhile, we see Eren opening the door to the kidnappers hideout. Suprised, they ask what he's doing here. He explains that he was walking in the woods and got lost. One of the men squats down and appears to be attempting to console him. Before the man can finish his offer to escort him out, Eren slits his throat with the knife he'd been concealing. Mikasa stares in disbelief, wondering if this is actually happening. With one of the men now dead, the other rushes toward Eren who is now behind the door he just entered from. As the man opens the door, Eren reveals a makeshift spear he has created from a broom handle and a knife (implying that he knew the situation before he entered the room and planned ahead). Charging towards the man, he thrusts the homemade spear into the upper right side of his chest, laying him flat on the floor but still alive. In a rage, Eren jumps on top of the man and using the knife from earlier, stabs him repeatedly, yelling that he had it coming.

With the second man bleeding out underneath of him, Eren now gains his composure. Wiping his face, he walks over to Mikasa cutting her ropes and trying to comfort her. He introduces himself and explains that he came with his father for the examination. Interrupting him, Mikasa reveals that there was a third man who then appears in the doorway. Shocked and angry at the sight of his friends, he attacks Eren, kicking him in the ribs and pinning him against the wall by his throat. Struggling to get the words out, he tells Mikasa to fight, otherwise they'll die. Mikasa grabs the nearby knife, but can't bring herself to take a life. However, seeing Eren gasping for air, triggers a flood of memories that lead her to realize that the world is a cruel and callous place. With this, she stops shaking and calms herself, gaining "perfect self-control". Now knowing what she needs to do, she rushes toward the man with such force that she twists and breaks the floor board beneath her feet, piercing his heart from his back.

With the police now at the scene, they are astonished at what the children were able to do. Eren's father however, is less than pleased. Hugging and chastising him, he asks him if he realizes what he's done, to which Eren replies, "Merely put down some rabid dogs! Sometime they just happen to look like people!". He tells Eren that he was lucky; the police might not have made it in time. When Dr. Yeager tells him that he threw his life away so easily, Eren tells him that he only wanted to save her as quickly as possible. Still traumatized, Mikasa tells Dr. Yeager that she needs to go home, asking for directions. Feeling the gravity of the situation, Mikasa says that she's cold and that she has nowhere to go since she's now homeless. Eren responds by wrapping his scarf around her neck with Dr. Yeager extending an offer for her to come live with them.

Back in the present, Mikasa is shown dispatching of Titans with relative ease and wondering when the withdrawal signal will sound. No sooner had the thought crossed her mind, when the bell rings. As her teammates are preparing to climb the wall, Mikasa heads to the front, thinking of Eren.

Desperate and running out of supplies, a group of soldiers uses tables and chairs in an attempt to fortify an upstairs room. With Titans surrounding the building and peering at them through the windows, the situation is bleak. When a Titan crashes their arm through the wall trying to get at them, a trainee decides that suicide would be preferable to getting caught and shoots himself.

Mikasa, reaching the front, joins Connie, Jean and other trainees on a nearby roof. With very little gas left in their 3D Maneuver Gear, they are unable to escape or help their comrades in the upstairs room. Jean reveals the reason for the supply shortage. Two trainees, charged with the task of supplying the soldiers, have barricaded themselves in the headquarters, too scared to go out. In an attempt to motivate the others, Connie declares that they should fight the Titans with the remaining gas, otherwise, they risk being in the same position as the upstairs group. In a morose yet realistic response, Jean asks if Connie really thinks they can make a difference given their current manpower. On another part of the roof, Sasha tries to raise morale, suggesting they pool their resources. She asks Armin, but he is still in shock. Reiner, Annie and Marco converse about the situation. They are soon joined by Mikasa, who asks where Eren's team is. They say that haven't seen him, point her to Armin.

Armin notices her running towards him, but can't bring himself to look her in the eye, thinking back on what happened. She asks if he is okay, still looking away, he doesn't answer. When she asks where Eren is, he bursts into tears. He then announces the casualties for his team, saving Eren's name for last. This has everyone's attention, especially those that were among the top ten in the 104th Trainees Squad. Armin begins to cry again. Mikasa comforts him, but dissociates herself from the news, appearing emotionless. She then repeats the advice Eren gave her years ago, if you want to live, you have to fight.

After shaming them into fighting, they follow her one by one. Armin notices that she isn't her usual clear-headed self and surmises that she's staying active to keep from shaking. Mikasa runs out of gas and falls, fortunately landing on a cloth covering. Thinking about the news, she worries that she is losing her family again. On the ground and without the mobility of the 3D Maneuvering Gear, two Titans start to close in on her. Remembering her friend, she says that she's had a good life, prepared for it to end. However, flashing back to the day Eren saved her life and him telling her to fight, she rises to her feet and readies herself for battle. As she is about to attack the oncoming Titan, the one at her back attacks it instead, smashing its face with a single punch. Suprised, Mikasa tries to figure out what's going on, as this Titan turns on its own species.

The fight's over and the Rogue Titan is victorious, he stands over the corpse and howls. Although confused, Mikasa thinks of the scene as uplifting, considering it the physical manifestation of humanity's anger toward the Titans. As she's focused on the scene, Armin rushes to her side and brings her to a nearby roof.

On top of the roof, Connie panics at the sight of the Titan. However, seeing the rogue Titan knocking another's head off causes them all to take pause. Observing that it went directly for a weak spot, Armin notices that it doesn't seem to react to humans like the others do and it seems to know hand-to-hand combat. With Mikasa completely out of gas, Armin offers up all of his gas and dulled blades minus one so as to not be eaten alive if caught. Mikasa, thinking of how she had given up, takes the blade from him and refuses to abandon him. Armin's protests mean little, when Connie takes Mikasa's side. Worrying that more of his friends will die, Armin comes up with a plan and leaves it up to Connie and Mikasa to decide.

Meanwhile, Jean Kirstein and a group of trainees try to make it to the HQ. On the ground, a trainee screams when he runs out of gas and sees Titans moving towards him. Another attempts to save him, only to be caught and put in the same situation. Jean and the others take the opportunity to dash toward the headquarters with the remaining supplies. Briefly caught by the leg, Jean cuts off the Titan's fingers and continues ahead. Managing to make it to HQ, he briefly questions his decision, until he spots the supply team. In a fit of rage, he grabs one of them by the collar and hits them. Marco breaks up the fight. Still furious, Jean blames them for the deaths of his teammates. When they tell him about the Titan in the store room, Jean tells them they should have made a plan so they finish their mission. Out of nowhere, a Titan rams his head through the wall, revealing that they are surrounded. As Jean is about to give up hope, Connie, Mikasa and Armin come crashing in through the window courtesy of an escort from the rogue Titan. With Armin's plan a success, Connie suggests utilizing it again, in the hopes that they can all escape. Jean and the other's scepticism is countered by Mikasa, who informs them that it is the only plan they have.

The Rogue Titan is still fighting the Titans outside and seems to be making short work of them. Sceptical, Reiner questions Connie about how much he actually knows about the Rogue Titan. Connie replies that he doesn't care, as it saved their lives.

With seven 3-4 meter class Titans in the supply room, they still aren't able to restock. Looking for anything that might help, the group finds some old guns in the headquarters. While some question their usefulness, Armin is able to form a strategy. Using the lift, one group, armed with the guns, will be lowered down into the room to get the Titans attention. When the Titans move in, they will fire into their eyes, temporarily blinding them. A second group, waiting above, will then jump down and go straight for their weak spot. The significant amount of risk, causes Armin to second guess himself; however, it's their only option. Mikasa comforts Armin, saying that his ability to strategize has saved both her and Eren in the past. He starts to ask when, but is cut short on getting an answer when the lift is prepared. The second group goes over their part and gets into position. Group one proceeds down the lift, quickly gaining the Titans attention. Nervous, they anxiously wait until the Titans are close enough. Nearly on top of them, group one fires their weapons into the faces of the giants. Group two then jumps down with everyone but Sasha and Connie killing their target. The others rush in to back them up with Mikasa saving Sasha and Annie saving Connie.

The room now clear and no more coming in, they move in to restock their dwindling supplies. As soon as their tanks are full, the group moves out except for Mikasa. Armin goes to see what's wrong. She notices the rogue Titan getting attacking and eaten by others and regrets that they couldn't learn more. Reiner, Jean, Annie and Berthold join them on the roof. Hearing the conversation, Reiner agrees with Mikasa and suggests helping it out. Jean isn't sure he's ready to risk his life for a Titan, especially since they just barely survived their last encounter. Annie also agrees with Mikasa, especially with the possibility of having a Titan as an ally. Out of nowhere, Armin catches sight of the Titan that killed Thomas. Suddenly, the rogue Titan bursts away from his attackers, lunging for that same Titan and bites through the back of its neck. In one motion, he slings the body in his mouth into another Titan, sending them both crashing through a building. With that, he collapses, seemingly exhausted. Jean, again questions if it can become an ally, saying a Titan remains a Titan. Without warning, smoke starts to rise from the back of the rogue Titans neck. Out of the smoke they see the body of Eren Yeager. Mikasa is the first to rush down, followed by Armin. Miraculously, he's alive and what's more, the arm and leg that were missing have completely regenerated. The others, surveying the dead Titans now see that it was the work of Eren and wonder if they do in fact have a Titan for an ally.

Because of the absence of the elite soldiers of the Survey Corps, so many soldiers' lives were lost. Back to the day of their departure, the soldiers entrusted with the mission this time are mankind's best and brightest soldiers. While out for the mission, one of the soldiers is caught by a Titan. Levi shows up and attacks the Titan, killing it. With reinforcements arriving, he orders Petra Ral to take care of the wounded. Commander Erwin approaches them on a horse, informing them that they must retreat. When Levi questions why, Erwin informs him of the latest attack on the city and the movement of the Titans toward it. Worried that the wall may already be broken, they leave.

Back to Eren, he wakes up seeing that soldiers have him backed into a corner, while Mikasa and Armin try to defend him. Eren begins to question himself why everyone is raising their weapon to them and glowering to him. If he manages to say something deceitful or move even an inch, a cannon is ready to shoot him anytime. The officer questions him asking if he is a human or a Titan and states that there were numerous witnesses that saw him coming out of the Titan, which in effect, makes him the enemy. Not wanting to risk any more soldiers, an officer near him suggests that they kill him while he's still in human form.

Mikasa informs the surrounding soldiers that if they try to get close to them, she would kill them. When the officer asks again what he is, he tells them he's human, the officer orders the cannons to fire on them. When he looks at the key, Eren thinks back to a time with his father. His father hands him a key and tell him the importance of keeping it with him and explains that the injections will cause memory loss. He also reminds him of the basement, the "power" would be useful and he would find answers there. As the cannon fires, Eren bites down on his hand. An explosion seemingly happens around Eren and his friends. When the smoke clears, the onlookers are shocked to see the hollowed out torso of a Titan with Mikasa and Armin safe inside.

Protected by the skeleton of Eren's partial Titan transformation, Mikasa and Armin silently watch as the Titan attempts to move, which scares Captain Verman even more, who orders the soldiers to stand by and prepare the cannon for next shot. Inside the Titan, Eren comes to his senses and gets out, surprised to see a figure of a Titan in front of him. He tells them that the basement of his house is an answer to everything and states that from now on, he must work alone, much to Mikasa's disagreement. However, Eren reveals the second plan. If Armin thinks he'll be able to persuade the Stationary Guard that he is mankind's ally, Eren will stay there. Armin walks out of the smoke and faces Verman and the rest of the soldiers. He tries to convince them that Eren isn't an enemy of mankind. However, Verman refuses to believe this and orders the soldiers to be ready for an attack.

Not giving up, Armin takes a posture of a soldier's salute and one more time asks for a permission to explain Eren's strategic importance, as they may even be able to recapture the town with Eren's powers. In spite of this, Verman refuses to accept this and attempts to give a signal for the cannon, but is suddenly stopped by Commander Dot Pixis, saying that he'd like to listen to what Eren and others have to say, he orders Verman to organize the reinforcements. On the top of the wall, he listens to Eren and others. Saying that Eren can prove himself now, he asks him whether he will agree on using his powers to move a giant rock and block the hole in the gate. Looking behind himself, Eren witnesses the area that would be lost if the gate were to fall and ultimately agrees with the plan. He undertakes Dot Pixis' order, even though he isn't sure about his power. Afterwards, he calls for a staff meeting to make a plan. Even though Armin believes that his plan is overly optimistic and not well thought out, Eren reassures him, saying that Pixis knows the situation and will plan accordingly.

When the soldiers hear about the plan to retake Trost, many are discouraged, believing they don't have the technology to get it done quickly enough. Pixis addresses the soldiers below, sharply getting their attention. He lays out the plan for the reconquest of Trost by sealing the hole Titans used for entering. Pixis introduces Eren to the soldiers as the one who will seal it by turning into a Titan. While Pixis explains the plan, Armin explains the plan in greater detail to two elite soldiers of the Garrison. A small group will be assigned to protect Eren while he moves the boulder to plug the hole. Armin though, feels unsure about the plan. On the ground, the plan is being met with resistance and disbelief. Large numbers of soldiers start to walk away. Pixis informs the group that whoever leaves will be pardoned, gaining the attention once again of the crowd. He states that they are putting their loved ones in the position of facing Titans. This makes turn around and go back to formation. Pixis then talks about what happened four years ago at Wall Maria. However, if Wall Rose was breached, humanity would not be able to get off with just twenty percent of the population being killed. With only Wall Sina left for them to live in.

Before the operation begins, Pixis orders Ian, Rico and Mitabi to guard Eren while he does his job. Pixis orders Ian to take lead in this operation. Ian then calls Mikasa and orders her to join the group that will protect Eren which makes Mikasa relieved. He then orders them to go into their position. They head for the shortest route and find no Titans in their way. As Eren and his group reach near the boulder, Eren bites his hand and emerges in his Titan form. However, he looks over his shoulder and surprisingly, attacks Mikasa. She manages to dodge Eren's punches and much to the rest of the team's surprise, she hangs herself at Eren's face in an attempt to talk to him. Meanwhile, Rico shoots a red signal flare as a message that the plan has failed. Seeing Eren getting ready to launch another attack, Ian warns Mikasa to get away from him just as Eren punches his own head as Mikasa manages to evade. The elite team then, much to Mikasa's discontent, discuss leaving Eren there and retreating.

On top of the wall, the soldiers witness the red signal flare. Seeing this, Armin decides to head to their location. However, Pixis orders the soldiers to continue luring the Titans and puts all his trust into the elite team. Back to the elite team, Mitabi decides to retreat, however, Ian orders them to take down the Titans nearing to their place, surprising everyone. Mikasa then notices that Eren's wounds aren't regenerating. Inside of the Titan, Eren is seen being barely conscious, not knowing where he is nor what he is doing. He then gets a vision of him being at home, being able to see his parents and Mikasa.

At that time, Armin arrives just to see injured Eren in his Titan form. Mikasa then realizes that it's Eren who's luring all the Titans in. She notices Armin who asks about the plan and Eren's state and tells him that Eren is unable to control the Titan. Armin stabs the Titan's nape, leading the blade through Eren's left arm inside of the Titan. He tells Mikasa to defend everyone from the Titans and then attempts to talk to Eren. However, Eren, in his vision, sees Armin from outside of the window and doesn't understand Armin's words. Armin asks him if he remembers that they want to explore the outside world. He questions his motives for doing so and Eren answers that it is because he was born to this world, just as his vision begins burning and the Titan with Eren inside wakes up.

The elite soldiers keep struggling in an attempt to defend Eren. However, Rico's squad ends up almost wiped out. As they are forced to retreat to the boulder's location, they witness the arrival of more Titans heading their way. The elite team, along with Mikasa, watching in surprise, that Eren is holding the boulder. Seeing this as their ultimate chance, Ian orders the soldiers to protect Eren even if it costs their lives. Finally reaching the hole, Eren, while being encouraged by Armin, drops the boulder, successfully blocking the entrance to Trost. Rico shoots a yellow signal flare as a message that the mission has been accomplished.

Seeing this, Dot Pixis immediately orders to send reinforcements and rescue the elite team. At that moment, two Titans reach them and as they are about to attack, they are slayed by Levi. Standing on top of the killed Titan, Levi looks at Eren and others and questions the situation. After that, both Stationary Guard and Survey Corps keep eliminating the Titans trapped inside Trost. Thanks to the cannons and Survey Corps's prowess, the area of Trost becomes free of Titans after a whole day of fighting. Not only that, but two Titans are also captured alive.

At an unknown place, Eren suddenly wakes up and sees Erwin and Levi of the Survey Corps. After being told that he is in an underground jail cell, being in the custody of the Military Police, Eren notices that Erwin is holding a key to the basement of his former house. Stating that he will give it back to Eren later, Erwin tries to confirm whether the basement holds the secrets of Titans, to which Eren replies that it's what his father said. Not trusting him, Levi states that it's convenient for Eren to have amnesia while his dad is missing, but Erwin insists that Eren has no reason to lie. They then ask Eren about what he wants to do and after recalling his past, he states that he wants to join the Survey Corps in order to slaughter as many Titans as possible. This catches Levi's interest as he walks forward and says that he will take care of Eren, not because he trusts him, but because he can kill him if Eren betrays them. He then tells Eren that he will accept his application to the Survey Corps.