Oathkeeper

Oathkeeper is the code name of an ancient spiritual Esper, the long-serving leader of the Holy Accord, and the current host of the Primal Esper Ability Entity Soul Flame. He spends an age preserving a promise made among the Primordial Ones: survive in secret, gather the keys to the Sanctums, and revive the dead founders of the organization in a later era. Suspicious and intensely protective of information, he initially treats Han Xiao as a dangerous outsider, but their cautious transactions become a strategic partnership that preserves Sanctum Revival, strengthens the World Tree defense, and gives historical Beyond Grade As a second life.

Biography

Mutation Disaster and the Secret War

The “Oathkeeper” name appears during the Mutation Disaster and Secret War, but it refers to a class of elite mechanical warrior created by Han Xiao, not to the Holy Accord leader. Those autonomous units have individual code names such as Warrior and Gunner, fight under Phillip, and are destroyed or rebuilt like other machinery. Their shared designation is a technological product name and does not indicate that the ancient Esper is present, controlling them, or connected to their construction. (Chapters 523, 570–571, and 658)

This distinction matters because the later Oathkeeper is a living spiritual Esper whose personal name remains unknown. Nothing in these early mechanical deployments establishes his biography, affiliation, or knowledge of Han Xiao. The overlap instead reflects two independent uses of the same word: one for Han's armored personal guards and one for a secretive individual defined by fulfilling an ancient promise. The character's first narrative scene occurs centuries of story history later, when the Holy Accord's leaders report to him. (Chapters 523, 658, and 1096)

The Evolution Cube and Crimson Dynasty

References to “a Primordial One” during the Evolution Cube era also do not by themselves identify Oathkeeper. The Mechanical Race descends from a deceased Beyond Grade A Mechanic, while the preserved body that becomes Spacetime Amber belongs to a different Primordial One whose ability froze spacetime. These figures establish how many unique pioneers existed during the exploration era, making Primordial One a historical category rather than a personal alias exclusive to the Holy Accord leader. (Chapters 760 and 837–838)

Oathkeeper remains hidden while those discoveries reshape Han Xiao's understanding of ancient Supers. The Federation of Light's records about the Spacetime Amber's creator demonstrate that some Primordial Ones left identifiable files, bodies, and inheritances; Oathkeeper has deliberately avoided that visibility. His absence is therefore part of his strategy rather than evidence that he is one of the ancient figures being discussed. By the end of the era, neither Han nor the universal civilizations have publicly connected the Holy Accord leader to a confirmed exploration-era identity. (Chapters 837–838 and 876)

Intelligent Plague and the Association

Oathkeeper first appears in command of the hidden Holy Accord. Black-robed and surrounded by soul-like flame, he receives reports from Law and Fay, both Beyond Grade As who still fear and respect him as their childhood teacher. He has led the organization for longer than they can remember and is powerful enough that neither expects to challenge him. When the contained Destiny's Child predicts that the First Sanctum's call has moved forward, he chooses to obtain the final Third Sanctum key personally rather than risk the plan after countless years of preparation. (Chapter 1096)

The needed fragment belongs to the Holy Light Particle under Han Xiao's control. Oathkeeper approaches through a spiritual projection and proposes a trade, but Han's unexplained knowledge of the Holy Accord instantly overturns the negotiation. Oathkeeper suppresses an impulse to silence him because Han is too strong to kill safely and because negotiation can still complete the mission. Han then exaggerates his intelligence until Oathkeeper becomes convinced there is a high-level traitor, prompting invasive memory scans and a temporary halt to Holy Accord activity. His defining caution protects the organization, but here it also makes him vulnerable to calculated bluffing. (Chapters 1097–1099)

Their relationship develops through repeated bargains. Oathkeeper trades portions of two Primal Esper Ability Entities and two advanced blueprints for the Holy Light Particle fragment, using disguised emissaries and an information-form escape plan to keep the Holy Accord untraceable. He is tense throughout but honors every promised term, and Han likewise lets the emissary leave. The successful exchange raises the Third Sanctum ritual's projected reliability and gives both men evidence that the other can cooperate without turning every secret into an immediate attack. (Chapters 1124 and 1141–1142)

Han's investigation of Soul Flame creates a second identity trap. Records identify its former master as Soul Emperor Rovell Sissock, leading Han to wonder whether Oathkeeper might be that supposedly dead Primordial One. The suspicion is never confirmed and is later disproved when the revived Primordial Ones recognize Sorokin as Soul Emperor. Oathkeeper is another ancient survivor who inherited or acquired Soul Flame; his true personal name and the exact history of that succession remain unrevealed. (Chapters 1130–1131, 1217, and 1241)

With the key assembled, Oathkeeper enters the Third Sanctum during the period when Han seeks help against the Soul Swapper. He cannot answer because time flows differently inside. The journey confirms that Sanctum Revival restores deceased Beyond Grade As from preserved information rather than from ordinary biological survival. Oathkeeper emerges carrying the knowledge and resurrection brand needed to complete the promise that defines both his code name and the Holy Accord. (Chapters 1164, 1198–1199, and 1202–1205)

Sanctum Revival and the Super Crisis

Oathkeeper activates the resurrection brand on an uninhabited planet rather than risk revealing the Holy Accord base. The first batch of Primordial Ones returns in weakened bodies, and he explains the modern universe before releasing them from personal obligation. He has revived them to keep his oath, not to possess an army: they may leave, seek revenge, or pursue new ambitions as long as they do not betray the Accord. He hopes some will stay, but refuses to compel them after accomplishing the common goal. (Chapters 1210–1211)

His generosity has a strategic boundary. Oathkeeper initially plans to conceal the repeatable nature of Sanctum Revival from Han, offering only technically true fragments while retaining control of the channel. Han demonstrates knowledge of the Great Reboot and Iterations, stripping away that advantage and forcing honesty. Oathkeeper then provides the real mechanism and accepts a division of labor: the Beyond Grade A Association will organize Supers openly, while the Holy Accord remains hidden insurance for those who prefer secrecy. Their aligned interest in Super survival finally becomes an explicit partnership. (Chapters 1212–1213)

Oathkeeper arranges Han's meeting with the revived founders despite lingering distrust. When five Primordial Ones challenge the younger Mechanic, he worries that Han has misjudged their strength, then watches Han defeat all five together. The result corrects Oathkeeper's own estimate—he had imagined a roughly even duel between himself and Han and becomes grateful that he never tried to kill him. More importantly, the demonstration tempers the revived Supers' arrogance, making them willing to study the modern era and consider the association instead of destabilizing it immediately. (Chapters 1214–1217)

The encounter with Sorokin tests Oathkeeper's secrecy under greater pressure. Sorokin infiltrates a Holy Accord member while hunting Soul Flame, recognizes the revived Primordial Ones, and threatens to broadcast the Sanctum secret through remote manifestations. Oathkeeper cannot guarantee that Soul Flame will block every signal, so he pauses the attack and entertains Sorokin's offer to join. He then informs Han despite having no formal duty to do so, judging the Black Star partnership more valuable than an opportunistic recruit from his own era. (Chapters 1239–1242)

Oathkeeper and the revived founders stage a false ambush with Han, lure Sorokin into exposing his full strength, and help destroy his physical shell. Han then pulls Sorokin's soul into the Underworld, whose isolation blocks every manifestation signal. The plan preserves Holy Accord's secret without accepting blackmail or killing a potentially useful combatant. Oathkeeper's participation shows significant development: the leader who once suspected every subordinate now risks a complex deception built on trust in Han and his undisclosed trump card. (Chapters 1243–1245)

Across the Super crisis, Oathkeeper continues gathering Sanctum keys and sharing high-level warnings. He remains outside public association politics, preserving Holy Accord as a strategic reserve rather than exposing every revived member to sanctions. His private relationship with Han allows information and resources to cross that boundary when necessary, making secrecy serve collective survival instead of becoming isolation for its own sake. (Chapters 1249, 1260, 1295, 1307, and 1315)

The World Tree War

Destiny's Child alerts Oathkeeper to a massive information convergence before the World Tree invasion becomes public. He summons Han, uses Soul Flame to communicate with the entity, and shares its fragmented images. Once Han explains the foreign civilization, Oathkeeper promises secrecy and agrees to produce more Sanctum keys. He understands that casualties among Beyond Grade As can also demonstrate unlimited revival, turning the Holy Accord's hidden accomplishment into a strategic answer to a war of attrition. (Chapters 1315–1317)

The Holy Accord initially contains factions that would rather avoid fighting for the three universal civilizations. Oathkeeper does not force every revived Primordial One into battle; he mediates between their historical grievances, the defense of their birthplace, and Han's need for reinforcements. Some eventually join the united front because flight would merely postpone the foreign threat, while others remain part of the concealed reserve. This approach preserves voluntary loyalty and keeps ancient resentments from breaking the alliance before they can contribute. (Chapters 1325, 1330–1331, and 1343)

Throughout the war, Oathkeeper's chief operational contribution is continuity. He gathers rare key materials, maintains the revival channel, and gives Han a reserve capable of replacing irreplaceable high-level combatants. Collection remains slow enough that a new resurrection cannot be improvised after every battle, so the accumulated keys are held for moments of strategic need. After more than ten years of work, the stockpile allows Han to conceal the true depth of the explored universe's Beyond Grade A forces and manipulate the World Tree's expectations. (Chapters 1364, 1404, and 1410)

The World Tree's defeat ends the mission that kept Oathkeeper rooted to the Holy Accord for ages. As the Supers Holy Land forms, Beiger becomes acting leader because Oathkeeper chooses to accompany Kasuyi beyond the explored universe. The decision is not abandonment: the revived founders are alive, the organization has successors, and Sanctum Revival is now protected by a larger coalition. Having fulfilled his oath, he can finally pursue discovery for himself instead of spending eternity guarding the return of others. (Chapters 1414–1419, 1445, and 1448)

Information Form and the Final Relay

At the departure dock, the first revived Primordial Ones surround Oathkeeper and acknowledge that he alone endured long enough to complete their shared project. He rejects praise and describes his work simply as keeping a promise, consistent with a life organized around duty rather than public recognition. Their gratitude nevertheless clarifies the scale of his accomplishment: generations passed, the original founders died, and the universal order changed, yet he preserved enough knowledge, personnel, and resources to bring them back. (Chapter 1448)

The farewell also reveals the warmth beneath his severe public manner. The Primordial Ones give him a discontinued Wayne Card set depicting their generation, and his usually expressionless face shows a slight smile. He then leaves with Kasuyi on a high-technology vessel whose journey may produce no news for a long time. Oathkeeper's final relay is institutional as well as personal: Beiger inherits Holy Accord's daily command, Han guards the revival system, and Oathkeeper carries the exploration-era promise into an unknown universe rather than remaining its solitary jailer. (Chapter 1448)

Appearance and personality

Oathkeeper initially appears as a hovering man in black robes whose edges seem to burn and release strands of black mist. His face is obscured, and his voice commonly reaches listeners directly through the mind. Spiritual projections take a similar form, with black flames gathering into a man in a black coat who remains invisible to everyone outside the chosen mental link. This presentation conceals both his identity and the boundary between his own soul power and Soul Flame. (Chapters 1096–1098 and 1124)

He is solemn, disciplined, secretive, and deeply suspicious, yet neither needlessly cruel nor obsessed with authority. A hint that Holy Accord has been exposed sends him into exhaustive internal investigation, and he considers killing Han or imprisoning Sorokin when either threatens the mission. In both cases he restrains the impulse when force would create greater danger. His caution can become comic paranoia, but it also sustains an underground organization across an age without losing sight of the promise that justifies it. (Chapters 1098–1099, 1124, and 1241–1243)

Oathkeeper's strongest moral trait is fidelity. He revives the founders without demanding obedience, tells them they may choose their own futures, and minimizes his sacrifice when they thank him. Trust comes slowly, but once Han repeatedly honors agreements, Oathkeeper shares secrets, resources, and strategic responsibility with him. His dry sarcasm, irritation at being outmaneuvered, enjoyment of Wayne Cards, and nearly hidden farewell smile give the ancient leader a human interior beyond the intimidating role. (Chapters 1142, 1211–1217, 1239, 1245, and 1448)

Abilities and class

Oathkeeper is a pinnacle Beyond Grade A spiritual Esper and an expert in souls. Law and Fay regard his strength as unfathomable even after reaching Beyond Grade A themselves, while Oathkeeper initially estimates that he might have an even chance against Han Xiao before seeing Han's later growth. The corpus does not provide a complete combat record or numerical profile, so his precise rank among other pinnacle Supers remains unconfirmed. (Chapters 1096, 1164, and 1216)

Soul tracing and spiritual projection

Oathkeeper can record the unique characteristics of a person's soul, trace that signature in a higher dimension, and project his consciousness directly to the target. The projection forms an exclusive mental link, allowing conversation while nearby observers remain unaware. It does not reveal the target's physical location and carries no combat capability, so it is a secure communication and contact technique rather than unrestricted teleportation or remote assassination. (Chapters 1097 and 1124)

Soul Flame

Soul Flame is a Super High Risk Primal Esper Ability Entity hosted by Oathkeeper. He amplifies it with his own pinnacle Beyond Grade A energy, producing starry flames that act on souls and minds instead of ordinary matter. Its known functions include scanning memories, stabilizing or communicating with unusual information entities, incinerating exposed soul energy, and imposing restrictions that prevent selected information from being disclosed. (Chapters 1096, 1099, 1130, 1164, and 1316)

The secrecy restriction punishes an attempted disclosure with soul backlash and alerts Oathkeeper, applying even to Beyond Grade A members such as Law and Fay. It is formidable but not perfect. Sorokin changes or partitions soul frequencies well enough to possess a member without immediate discovery and can threaten simultaneous disclosure through distant manifestations, leaving Oathkeeper unsure that every signal can be stopped. The Underworld's complete communication isolation is required to close that loophole. (Chapters 1099 and 1239–1244)

Soul Flame also lets Oathkeeper attack on an enormous scale. When a disposable fleet assaults a Holy Accord base, an expanding illusory ring burns away more than ninety percent of the crews' souls while bypassing their ships' material structure. The event confirms that his intimidating reputation is not merely organizational. However, the corpus does not establish whether every displayed Soul Flame effect belongs to Oathkeeper alone or combines his control with other Holy Accord defenders, so exact battlefield attribution should remain cautious. (Chapter 1240)

Mental examination and defense

Oathkeeper can penetrate voluntarily lowered mental barriers and rapidly review memories, as he does while investigating the imagined Holy Accord traitor. Soul Flame's prohibitions and his own spiritual awareness make ordinary betrayal extremely difficult. Other experts can still conceal information through specialized soul mechanics, and he acknowledges uncertainty rather than pretending his surveillance is absolute. That willingness to recognize a limit is central to his handling of Sorokin's threat. (Chapters 1099 and 1241–1242)

Sanctum knowledge

Entering the Sanctums and activating their resurrection brands are learned procedures, not Oathkeeper's Esper ability. He knows the Third Sanctum method, which assembles a key from Primal Esper Ability Entity fragments, and he uses Destiny's Child revelations to improve the process. Time-flow differences can keep him absent from the main universe for an uncertain interval, and every use consumes keys that must be gathered again. His mastery is logistical and informational rather than a power to revive anyone at will. (Chapters 1096, 1141–1142, 1164, 1198–1213, and 1364)

Relationships

• Han Xiao: Oathkeeper first views Han as a dangerously informed outsider and possible target, but negotiated exchanges establish mutual reliability. Han forces him to reveal the full Sanctum mechanism, after which they divide open and hidden responsibility for Beyond Grade A survival. Their partnership solves the Sorokin crisis and supplies revival reserves throughout the World Tree war. (Chapters 1097–1099, 1142, 1212–1213, 1242–1245, and 1316–1404)
• Beiger: Beiger is one of the revived founders whom Oathkeeper returns to life. He supports Holy Accord operations, helps identify Sorokin as Soul Emperor, and eventually becomes acting leader when Oathkeeper leaves with Kasuyi. Their relationship moves from keeper and revived founder back toward colleagues from the same ancient project. (Chapters 1210–1217, 1241–1245, and 1445–1448)
• Pangon: Pangon is another revived Primordial One and a founder of the Holy Accord. Oathkeeper respects his freedom even when revenge makes him difficult to direct, while Han's demonstration of modern strength helps temper his impulsive confidence. (Chapters 1210–1217 and 1343)
• Sorokin: Oathkeeper inherits Soul Flame from the era after Sorokin possessed it as Soul Emperor. When Sorokin comes to reclaim it and discovers Holy Accord, Oathkeeper contains the threat through negotiation, then works with Han to trap his soul in the Underworld. Their conflict finally resolves the mistaken suspicion that Oathkeeper himself was Soul Emperor. (Chapters 1130–1131, 1217, and 1239–1245)
• Feidin: Feidin acts as Han's trusted emissary in the exchange that gives Oathkeeper the Holy Light Particle fragment needed for the Third Sanctum key. Oathkeeper coordinates the handoff through spiritual projection while keeping the Holy Accord emissary's route concealed. (Chapter 1142)
• Kasuyi: Kasuyi shares Han and Oathkeeper's interest in the truth behind the Sanctums and the wider universe. After the World Tree war, he and Oathkeeper leave the explored universe together, converting a wartime alliance into a long-range expedition. (Chapters 1213, 1364, 1445, and 1448)
• Hila and Aurora: Oathkeeper cooperates with the inheritors of the Underworld, whose soul prison provides the certainty Soul Flame cannot achieve against Sorokin's manifestations. Their revival and Hero Spirit capabilities later complement Holy Accord's Sanctum channel during the World Tree war. (Chapters 1244–1245, 1338, and 1359)

Items

• No individually tracked signature item: Oathkeeper controls Soul Flame as its host and gathers consumable Sanctum keys, but neither is an ordinary possession in the supplied approved item inventory. The corpus assigns him no separately tracked personal weapon, armor, or artifact.