After an uneasy rest during which he dreams of his childhood with Gambino, the mercenary who had raised him unwillingly, had him raped, and tried to kill him, Guts awakens in the camp of the Band of the Hawk. He is approached once more by Griffith, who had taken a shine to Guts after watching him in the previous battle and offers to induct him into the Band. Guts, however, refuses to be bound to anyone and decides to settle the matter with a duel, the stakes being Guts's freedom and Griffith's life. Both Guts and Griffith prove to be an even match for each other, but Griffith ultimately manages to overpower Guts, dislocating his shoulder and winning the duel. He then confides in Guts that he has a dream; to lead a kingdom of his own.
In the years since, the Band of the Hawk become a force to be reckoned with, helping Midland win a number of decisive battles and Griffith knighted as a viscount, much to the nobility's chagrin. Guts goes on to be the leader of the Hawks' raiders, although his reckless fighting style draws the ire of Casca, a female soldier and devoted follower of Griffith with whom Guts often butts heads.
During one battle, Guts learns that several soldiers have been caught by surprise by a powerful warrior known as Nosferatu Zodd. Guts and Griffith confront the warrior, who transforms into a fearsome monster and overpowers them. Before Zodd can kill Griffith, however, he sees something peculiar hanging around his neck. This forces Zodd to withdraw, but not before warning Guts that his continued association with Griffith would lead to his doom.
As Guts and Griffith recover from the battle, Griffith shows off the object that had chased away Zodd: a crimson Behelit, which Griffith received as a child from an elderly shopkeeper who claimed its owner would rule the world in exchange for their flesh and blood.
As Griffith's standing within the kingdom grows stronger, he becomes friends with the king's daughter, the fair princess Charlotte. Julius, the king's brother, finds this disconcerting as it would potentially jeopardize his right to succession. During a hunting game held by the nobility, Julius isolates Griffith while he is chasing after Charlotte, whose horse had been startled, and tries to assassinate him with a poison-tipped arrow. Thankfully, Griffith's Behelit blocks the arrow and prevents it from piercing his skin.
Afterwards, Griffith confides in Guts that he had researched the poison laced into the arrow fired at him, discovering it was unique to Julius's family. He asks for Guts to carry out an assassination on Julius.
That night, Guts sneaks into the castle and, when Julius is alone, executes him. Guts notices he has been seen in the act and silences the witness, only to realize that the witness was Julius's young son, Adonis. Guards see the masked Guts over Adonis's body, and Guts makes a hasty retreat, reeling from having accidentally killed a child.
Afterwards, Guts seeks out Griffith, the guilt from killing Adonis weighing greatly on him. Casca informs him that Griffith is at a ball and, when Guts goes to meet with him, stops him. The two end up overhearing a conversation between Griffith and Charlotte, where Griffith explains his philosophical ideas about war and what drives men to fight. When Charlotte says that his soldiers were lucky to count him as a friend, Griffith corrects her; while he is thankful to his men for their loyalty, he admits that he cannot consider any of them as a friend. He explains that, to him, a friend is someone who has a reason to live beyond himself, a dream that they are willing to pursue at any cost, even if it means opposing him.
As the ball ends amidst news of Julius and Adonis's deaths, Guts walks away, realizing that his own desire to help Griffith achieve his dream means that they may not be friends like he thought, a notion that leaves him greatly troubled...
Casca dreams of the day she met Griffith when he saved her from being beaten and raped by a noble she had been sold off to. When she awakens to find Guts with her, she lashes out at him, angry with herself and the apparent weaknesses she suffered from as a woman, and her own increasing reliance on Guts.
Cut off from the Band of the Hawk, Guts and Casca disembark from the cave when the weather breaks to rejoin their allies. Along the way, they are cornered by Adon and his soldiers who are prepared to kill Guts and violate Casca. Guts gives Casca an opportunity to escape and find Griffith while he fights off Adon's soldiers. By the time Casca returns with Griffith and the other Hawks, they find the forest where she left Guts strewn with the bodies of over a hundred soldiers. Guts is found leaning against a tree, heavily injured, but alive. With Adon captured, the Hawks celebrate their victory and cheer for Guts, the Hundred Man Slayer.
Even with this victory, however, Midland and Chudor are at a stalemate. At the center of this stalemate is Doldrey, a border fortress that Chudor had taken from Midland. All attempts to retake Doldrey have failed, and morale is beginning to decline as a result. Griffith, who had gained much prestige and influence in light of Julius's death, proposes a daring plan: rather than sacrifice more Midland soldiers, he would recapture Doldrey with only his own Band of the Hawk soldiers. The plan proves controversial, but the King gives Griffith permission to proceed.
What follows is an intense battle of wits and strength between the Band of the Hawk and Lord Gennon, the general leading Doldrey with whom Griffith once had relations. Gennon is joined by Boscogn, the leader of Chudor's elite Holy Purple Rhino Knights; and Adon, who had been reassigned to Doldrey following being disgraced from his capture. In the ensuing battle, Guts slays Boscogn while Casca gets her revenge on Adon and aids the Hawks in seizing the fortress. Gennon, defeated, is taunted by Griffith, who claims he only entered into a relationship with him out of convenience; without his considerable wealth, he wouldn't have been able to form the Band of the Hawk, and Gennon wouldn't have been defeated. As Gennon realizes he had been played for a fool, Griffith kills him.
With the Battle of Doldrey won, the Band of the Hawk are welcomed back to Midland as heroes. During a celebratory ball that evening, the King announces that, in recognition of his service, Griffith would be made a general of Midland's military, with his Band of the Hawk being inducted into the military with him as the White Phoenix Knights. Griffith and his men celebrate as they are finally made into nobles.
All throughout the battles with Chudor, however, Guts finds himself increasingly troubled by what he overheard Griffith say following his assassination of Julius; that a true friend, to him, is someone with a dream of their own, someone who is not simply content to help Griffith achieve his dream. Wishing to be the kind of man worthy of being Griffith's friend and equal, Guts makes a fateful decision; after the ball concludes, he decides to leave the Band of the Hawk.
As he leaves Midland, Casca and other Hawks try to convince Guts to stay. Guts is determined to leave, but is confronted by Griffith, who warns Guts that if he wanted freedom, he would have to take it back the same way he lost it. Guts reluctantly obliges Griffith, and the two men draw their swords. The duel ends almost instantly; when their swords clash, the cold air making Griffith's saber brittle and shattering it. Having defeated Griffith, Guts walks away, leaving Griffith devastated.
In an attempt to get over Guts's departure, Griffith sneaks into Princess Charlotte's bedchamber and seduces her. While having sex with her, however, his thoughts keep turning to Guts, and he feels disgusted with himself afterwards. While departing the castle the following morning, he is captured by Midland soldiers; a castle maid saw Griffith having sex with Charlotte and reported it.
As the Band of the Hawk are lured to an isolated field and ambushed by Midland soldiers, Griffith is imprisoned and tortured by the King before leaving him to his worst torturer. The fates of Griffith and the Band of the Hawk hang in the balance as Guts tries to find his own place in the world...
While most of the Hawks are pleased to see Guts return, Casca is livid. When the two are alone, Casca forces Guts to fight her. During the fight, Casca screams at Guts, blaming him for Griffith's weakness and the series of events leading to their current state. Guts takes a sword blow as the full gravity of his role in Griffith's downfall hits him. Casca, finally coming to terms that she could never be Griffith's protector, nor would he reciprocate her feelings for him, asks Guts to protect the Hawks before throwing herself off a cliff. Guts, however, saves Casca from falling, in spite of his wound.
As Guts berates Casca for acting so recklessly, Casca finally comes to realize that she was in love with Guts. When Guts realizes his feelings for her, he reciprocates, and the two make love. While resting with Casca afterwards, Guts is approached by the Skull Knight, who warns the "struggler" that a great darkness was coming.
A few days afterwards, Guts leads the Hawks in their mission to rescue Griffith. They travel to the deepest, darkest dungeon in Midgard, where they find Griffith. The Hawks are taken aback at Griffith's condition; his tongue had been cut out, leaving him unable to speak; the tendons in his wrists and ankles had been cut, leaving him unable to walk or hold a sword; and his face is so horrifically scarred that Guts cannot bear to look without Griffith's helmet concealing the scars.
The Hawks break out of the dungeon and evade their Midland pursuers, escaping with Griffith in tow. The Hawks make their way to Midland's border, where their fate remains precarious due to Griffith being rendered an invalid. Griffith, disgusted with himself for being so weak and unable to achieve his dream any longer, forces himself onto Casca as she treats his injuries. Casca resists at first, but eventually gives in.
Afterwards, Guts sees Casca, troubled over Griffith's advances. Griffith watches as he sees Guts and Casca closer to one another than he remembered. Guts resolves to stay with the Hawks and look after Griffith with her, but Casca states that if he considered himself a true friend of Griffth, he would leave and find his own dream.
Griffith, unable to bear the reality of his situation any longer, uses what little strength he has to force the horses moving his carriage to run. As Guts and the Hawks give chase, the carriage crashes and Griffith is thrown into a shallow river, breaking his arm. Griffith tries to kill himself by piercing his throat on a nearby branch, but he has become so weak that he lacks the strength to even end his own life.
As he lays in the river in despair, he sees something surprising: his crimson behelit, which he lost around the time he was captured. He picks up the behelit as Guts and the Hawks approach him.
Just as they reunite, an eclipse blocks out the sun, and the behelit, awakened by Griffith's blood, lets out a blood-curdling scream. The Hawks find themselves transported to a bizarre hellscape, surrounded by monsters beckoned by the behelit. Four wicked demonic gods known as the Godhand appear before the Hawks, summoned by the behelit, to give Griffith the chance to join them as a demon. The only condition is that he sacrifice the flesh and blood of his friends to the demons gathered. To influence Griffith's decision the Godhand show him all of the death and devastation he left in his wake as the leader of the Hawks; he had come so far to achieve his dream, he couldn't afford to stop.
As Griffith considers accepting, Guts shouts out to him. Griffith chuckles as he looks to Guts and makes his decision;
"Among the thousands of comrades, and ten thousands of enemies, you are the only one who made me forget my dream...I sacrifice."
With Griffith's consent, the Band of the Hawk are branded for sacrifice as Griffith is placed in a cocoon. The demons proceed to visciously slaughter all of Guts's friends while he desperately fought them off.
Eventually, Griffith emerges as a demon, Femto. Now commanding the demons, Femto has Guts pinned down as he uses his gravity powers to bring forth Casca, whom he proceeds to viciously rape while staring Guts dead in the eye. Guts fights against the demons, losing his left arm and right eye in the process, but is powerless to stop Femto. As he falls into despair, the Skull Knight appears, fighting off the Godhand and their demons and escaping with Guts and Casca.
Guts has a dream of his friends in the Band of the Hawk, watching as they walked away in a fog, deaf to his voice. When he reawakens, he finds himself in the home of Godo and his granddaughter, Erica. Rickert, the other lone remaining Hawk who escaped death by being far away from the others when the Eclipse came, tells Guts that the only other survivor is Casca, who is in a quarry nearby. When Guts tries to approach Casca, however, she screams and runs from him, unable to remember him, or even to speak. As a result of what she was forced to endure, she had been driven insane.
Guts is crestfallen at what had happened; his friends were dead, his lover was changed for the worst, and it was all because of the man he thought of as his best friend. He runs through the fields and forest, as though to escape, before collapsing in exhaustion. As the sun sets, the scar from Guts's brand begins to burn, and demons assail him. The Skull Knight appears, telling Guts that because of his brand, he is now trapped between his realm and that of demons. Guts, unwilling to give in to the demons, takes the Skull Knight's sword and fights off the demons until the sun rises, and with its light, the demons vanish.
Vowing revenge on Griffith, Guts dons his new black armor, taking the Dragonslayer sword and a new prosthesis and setting out to kill the man who was once like a brother to him...
