Bercouli Synthesis One

Bercouli Synthesis One is the Integrity Knight Commander with first rank in the Axiom Church’s hierarchy.

He appears as a man in his forties to fifties with bronzed hair and a large, powerful build, but has actually lived for over 200 years due to memory alteration and life extension by Quinella.

His name reflects “One,” because he is the very first person whose memories were rewritten to become an Integrity Knight.

Despite his loyalty in form, he has long harbored doubts about the origins of the Integrity Knights and the nature of the Axiom Church itself.

Bercouli is admired and affectionately called “Uncle” by Alice Zuberg, who deeply respects him as both mentor and family.

He has fought dark knights from the Dark Territory multiple times and has never lost to another Integrity Knight, highlighting his status as the strongest knight.

He uses a style similar to the Norcia school, focusing purely on overwhelming power in a single strike rather than flurries of attacks.

Normally such a style is weak against continuous sword techniques, but when combined with his Time Piercing Sword, he overcomes that weakness and dominates both offense and defense.

Bercouli’s insight is exceptional, allowing him to immediately see that Kazuto Kirigaya’s Aincrad-style sword skills are not showy, ritualized techniques like those of Human World swordsmen, but lethal, practical combat arts born from real life‑and‑death battles.

He can also “feel” time very accurately thanks to his deep connection with his sword, effectively measuring time in a world without clocks.

In the anime adaptation, his voice actor is Junichi Suwabe.

The article content primarily reflects the Sword Art Online: Alicization anime; details differ slightly from the original novels.

The Time Piercing Sword is a divine object forged from the hands of the “Clock” (also called the System Clock) embedded in the wall of the Central Cathedral.

In earlier media it is depicted as a katana, but the anime redesign portrays it as a large sword.

This weapon is one of the strongest divine objects in Underworld, possessing the ability to manipulate the flow of time on a systemic, log-based level.

It does not literally bend real time and space; instead, because Underworld is a virtual world, it interacts with current and past logs of events, creating the effect of temporal manipulation.

Through this sword, Bercouli can unleash techniques that “cut the future” or even “cut the past,” striking at targets in ways that bypass conventional defense, evasion, and even most forms of Incarnation-based protection.

His bond with the Time Piercing Sword is so deep that he can sense precise durations, enabling him to use its more demanding techniques.

Weapon Control Art: Karagiri (“Empty Slash” / Future Cutting Technique)

Bercouli’s weapon control art, often called “Empty Slash,” allows him to slash a point in the immediate future rather than the present.

He predicts the enemy’s movement, cuts the empty air where they will be, and when they move into that location a moment later, the stored slash is applied to them as if he had struck in real time.

From the original depiction, it appears the activation timing can be adjusted even after the sword is swung, so he is not literally leaving a slash “hanging in the air” but functionally achieves the same result.

This makes it extremely difficult to even get into close range against him, as any attempt to close the distance can be preemptively punished by future slashes.

Karagiri was born from desperation early in Bercouli’s career as an Integrity Knight, after he was utterly outmatched by a dark knight who used continuous sword techniques.

To land a single blow against such an opponent, he devised a way to preserve the power of a single strike and apply it with the reliability of a multi‑hit combo.

As Kazuto Kirigaya remarks in Sword Art Online: Alicization Lycoris, Karagiri allows Bercouli to retain the destructive power of a single heavy blow while still achieving the hit rate of rapid-fire techniques, combining the best of both worlds.

In practice, this means that sword-style matchups matter far less against him, because his time-cutting ability covers many inherent weaknesses.

Bercouli is also very capable at medium and long range, and he states he has never lost to another Integrity Knight.

Together, his technique and his weapon make him a nearly flawless fighter, feared by both Human Empire and Dark Territory forces.

Memory Release Art: Uragiri (“Back Slash” / Past Cutting Technique)

Uragiri is Bercouli’s ultimate, forbidden Memory Release technique, used to “cut the past.”

By exploiting Underworld’s system logs, it forces the system to misinterpret the target’s past movement coordinates as their current position and then cuts those past coordinates, producing an unavoidable strike.

Because it directly interferes with the system’s perception of position, this attack bypasses normal defenses, evasion, and even Incarnation-based defenses, functioning almost like a system-level hack rather than a conventional sword skill.

Bercouli strongly dislikes this technique, believing that it “betrays all effort and technique” by ignoring the opponent’s skill and preparation, and so he seals it away as much as possible.

Importantly, Uragiri can only precisely target exactly ten minutes in the past.

In a world with no physical clocks, measuring an exact ten minutes purely by personal sense is extremely difficult, especially in combat.

Even if one knows the timing, in a fast-paced fight where the target’s coordinates change constantly, picking the right logged position is incredibly demanding.

Because of this, only someone with Bercouli’s absurdly honed senses and experience can use Uragiri effectively; for most people it would be unusable rather than overpowered.

Bercouli refuses to use Uragiri in his battle with Eugeo, despite knowing that doing so could secure victory and protect the Axiom Church’s interests.

He fears that using such a system-breaking trump card against a young swordsman would amount to betraying his own values as a warrior, and potentially constitute a betrayal of the Axiom Church if misused.

Bercouli is unusually relaxed and approachable compared to the generally serious Integrity Knights.

He speaks in a casual, friendly manner, calling Alice “little Alice” and even asking Eugeo to “wait a bit” while he finishes soaking in the bath before their duel.

He dislikes fighting driven purely by hatred or resentment and prefers battles of honor between warriors.

However, he is not indifferent to the dignity of his comrades: when he learns that Fanatio Synthesis Two lost to Kazuto Kirigaya and Eugeo, he insists on confirming her condition and seeks suitable retribution, showing he strongly values his fellow knights.

Bercouli presents an air of calm confidence and maturity, but he also has a teasing, almost playful side that disarms people around him.

Despite his doubts about Quinella and the church, he does not consider his time serving under her purely negative and retains complex, nuanced feelings toward her.

To Alice, he is both commander and family, someone she can call “Uncle” without hesitation.

His warmth, humor, and overwhelming strength together make him a pillar of the Human Empire’s forces and a central emotional figure in the Alicization arc.

Early History and Hidden Identity

Long before he became an Integrity Knight, Bercouli was a legendary swordsman of the Human Empire.

Three hundred years before the current storyline, he founded Rulid Village and served as its first guard captain, becoming the hero of the village legend later told to Eugeo and Alice Zuberg as children.

After being taken by the Axiom Church, Bercouli’s memories were rewritten by Quinella.

As a result, he forgot his own past, including that he had once shared peaceful moments with the White Dragon of the North, which he later killed as an Integrity Knight under church orders.

In the Underworld: Reflection (UR) arc, Eolline reveals that Bercouli was born into the noble Harlence family, a lineage that was later extinguished.

This connects him to the Human Empire’s noble structure and underscores how deeply his original identity was buried.

Encounter with Eugeo in Central Cathedral

In the anime, Bercouli returns from a flying dragon expedition and heads to the large bath on the 90th floor of Central Cathedral to recuperate.

There, he encounters Eugeo, who is ascending the tower alone at that point due to various circumstances.

Even after learning that Eugeo and his companion defeated Fanatio and others, Bercouli remains calm and friendly in demeanor.

However, he still takes the situation seriously and begins a duel with Eugeo while still in a light robe, demonstrating his confidence.

At first, Bercouli completely dominates Eugeo with the power of the Time Piercing Sword and his future-cutting technique, leaving no openings to be exploited.

Eugeo, pressured to the limit, responds by using the Memory Release of his own sword, turning the entire floor into a deadly environment of ice.

The fight ends with both of them frozen, making it essentially a draw, though Bercouli is defeated in the sense that Eugeo’s final, self-sacrificing strike breaks through his advantage.

Immediately afterward, Chudelkin appears and furiously scolds Bercouli for “losing” to Eugeo and for the chaos caused.

When Bercouli retorts that he should not interfere with a duel between swordsmen, Chudelkin uses his high-level authority and the sacred art “Deep Freeze” to turn Bercouli entirely into stone.

Bercouli is thus removed from the battlefield before he can play a role in the final confrontation with Quinella.

Support to Kazuto and Alice During Stone State

While petrified, Bercouli remains conscious enough to perceive what is happening around him.

When Kazuto Kirigaya and Alice Zuberg arrive at the scene after Eugeo has been taken away, Bercouli warns them of Eugeo’s abduction and urges them to hurry to the higher floors.

He is fully aware that speaking may cause his stone body to crack and shatter, but he still chooses to risk it to aid the younger swordsmen.

This moment shows his willingness to sacrifice even his body to give them a chance to save Eugeo and confront Quinella.

After Quinella and Chudelkin are ultimately defeated, Bercouli’s petrification is undone.

With the Axiom Church’s old leadership gone, he temporarily assumes practical control and becomes responsible for reorganizing the Human Empire’s defense.

Reorganizing the Human Empire Army

Bercouli quickly reforms the Human Empire’s military forces to prepare for the coming Final Load Experiment, also known as the Great War against the Dark Territory.

He scrapes together a new army from Integrity Knights and human forces, all while dealing with severe shortages of manpower and combat power.

Even with a critical lack of absolute strength, the newly organized army benefits from the removal of empty rituals and rigid formalities that had plagued the Axiom Church’s system.

This more practical, honest approach raises morale, and Bercouli pushes everyone to make the most effective, realistic preparations possible under heavy constraints.

He trains knights and volunteers alike, treating them not as disposable assets but as comrades whose resolve matters.

This leadership style earns him loyalty and makes the Human Empire forces much more resilient than their raw numbers would suggest.

Final Load Experiment and the War Against the Dark Territory

During the final load experiment, the large-scale invasion known as the war against the Dark Territory begins.

Bercouli takes command on the front lines, coordinating the Integrity Knights and the Human Empire’s forces.

Using the Weapon Control Art of the Time Piercing Sword, he executes a plan to completely annihilate the enemy’s aerial minion forces.

By precisely timing his future-cutting slashes, he destroys the flying units as intended, significantly weakening the Dark Territory’s air superiority.

However, when Alice is kidnapped by Emperor Vector, the super-account used by Gabriel Miller, Bercouli chooses to pursue alone.

He rides his flying dragon Star Eater, chasing Vector in an attempt to save Alice and stop the emperor.

In the confrontation with Emperor Vector, Bercouli faces an overwhelming foe whose account authority and Incarnation are extremely powerful.

During the battle, Vector cuts off one of Bercouli’s arms, and his beloved flying dragon Star Eater is killed.

With his options exhausted and his body failing, Bercouli finally decides to use his forbidden Memory Release Art Uragiri.

He bets his life and the entire durability of the Time Piercing Sword on this single strike, aiming to cut Vector’s past and bypass all defenses.

By precisely measuring ten minutes and exploiting the system logs, Bercouli’s slash lands as an inescapable blow that Emperor Vector cannot block or evade.

This decisive strike defeats the super-account and saves Alice, marking an enormous victory for an artificial Fluctlight against a real-world human operator using one of Underworld’s strongest accounts.

After the battle, Bercouli carries the rescued Alice on his back as far as he can.

His life finally comes to an end, bringing closure to more than two centuries of existence as a swordsman, founder, and knight.

In his final moments, he reflects on his life, including his complicated but not entirely negative feelings toward Quinella.

He also remembers his companion Star Eater and their first meeting, passing away with those memories engraved in his heart.

To outside observers from the real world, the Emperor Vector avatar was “replaceable,” but within Underworld, Bercouli’s victory is enormous.

He accomplishes what even Kazuto Kirigaya struggled to achieve, striking down a chapter-final boss-level foe as a being born entirely within the simulation.

In Sword Art Online: Alicization Lycoris, Bercouli serves as head of the Anti-Monster Countermeasures Headquarters.

He coordinates Integrity Knights and volunteer hunting parties, which gives him far more screen time and interactions than in the original light novels.

The game allows for deeper interaction between Bercouli and Kazuto Kirigaya, who comes to respect Bercouli greatly while still finding him hard to read.

Bercouli, in turn, highly praises Kazuto’s sword, calling it a blade that “cuts in faster and stronger than anyone else’s” and “never stops evolving.”

He acknowledges that Kazuto’s arrival has finally shaken the long-stagnant Axiom Church system, and he views that change positively.

Bercouli’s open-minded acceptance of change underscores his difference from the more rigid church officials.

In more comedic and slice-of-life scenes, Bercouli shows off impressive versatility.

He easily detects Kazuto trying to tail him, demonstrating both keen perception and a bit of playful superiority.

He also shares light, character-driven moments with Fanatio Synthesis Two, who in the main story is strongly attached to him.

Bercouli shows textbook “I just made too much food by accident” tsundere behavior toward her, while also appearing in bath scenes that highlight his muscular physique, making him unexpectedly popular with female players.

He trusts Kazuto’s judgment of people enough to assign him the task of scouting talented individuals.

This indirectly leads to Kazuto reuniting with characters from drama CD stories, a bit of a “hidden good play” on Bercouli’s part.

In Lycoris, his equipped weapon is described as a katana, matching the original novel’s depiction of the Time Piercing Sword.

However, because of the anime-based redesign, he visually appears like a two‑handed sword user, so players must be careful not to misread his weapon type when equipping gear.

There is also a special paid skin for the Time Piercing Sword: a simplified, original‑novel-style version labeled as a “veteran” variant.

It comes with a flavor explanation that it appears from the distant future, adding a mysterious edge to his already legendary weapon.

Bercouli’s true origins are finally revealed late in the story.

He is the heroic swordsman of legend from Rulid Village, the same village where Eugeo and Alice were born and raised.

The childhood legend that Eugeo and Alice heard about a great swordsman who saved their village refers to Bercouli himself.

Tragically, after becoming an Integrity Knight and losing his memories, he was ordered to slay the White Dragon of the North—a creature with which he had once shared gentle, friendly moments.

In the climactic war against the Dark Territory, Bercouli uses Uragiri to strike down Emperor Vector in a mutual death scenario.

He dies in the process, ending a life of over 200 years filled with battles, service, and quiet doubts.

For Underworld residents, Bercouli’s achievement is monumental.

He proves that an artificial Fluctlight, born entirely in a virtual world, can defeat a top-level external intruder wielding a super-account.

His death deeply affects Alice and the other Integrity Knights, who inherit his will and continue fighting to protect the Human Empire and the Underworld as a whole.

His actions help pave the way for the eventual liberation and transformation of Underworld beyond the control of the old Axiom Church.

Even after his death, Bercouli’s influence remains strong.

He is remembered as a relaxed yet unshakable Knight Commander, a founder of villages, a pioneer of time-cutting sword techniques, and a warrior who chose to uphold his own sense of honor, even when it meant using a power he despised in order to protect those he cared about.