Demon King of Incarceration

The Demon King of Incarceration is an ancient former Hero who becomes a Greater Demon King after his closest companion betrays him and transforms into Destruction. Unable either to kill Destruction or be killed by it, Incarceration repeatedly rebuilds the world after each apocalypse and tests later eras for a force capable of ending the cycle. His covenants with Vermouth create the three-hundred-year grace period in which Eugene and his companions grow strong enough to defeat him, after which he helps contain Destruction and willingly gives his body to preserve Vermouth's soul. (Chapters 19, 546, 579–594, and 612–613)

Biography

The Covenant Behind the New Era

Incarceration begins in a forgotten era as a Hero carrying divine power. He defeats that era's Demon King, but companions corrupted by temptation and curses turn against him; his dearest friend stabs him in the back, claims the Demon King's throne, and devours power until he becomes Destruction. Incarceration falls into corruption himself to escape being consumed and binds Destruction with the first of his chains. The connection prevents either from killing the other, changing his original victory into an eternal obligation to survive the disaster his former companion created. (Chapters 583 and 586–587)

Whenever Destruction annihilates an era, Incarceration preserves and processes souls, raises land from the flooded ruins, restores the circulation of life, and waits as civilization forms again. He then resumes the role of Demon King so that a future Hero can be tested before Destruction returns. Repetition makes compromise his governing belief: because he cannot end the calamity, he accepts the destruction of each present world in order to create another. The system preserves life in aggregate, but it also turns individuals, nations, and even loyal servants into resources for an era Incarceration alone plans. (Chapters 580 and 586–587)

Vermouth's unprecedented separation from Destruction gives Incarceration a possibility absent from earlier cycles. Their first covenant grants Vermouth time to gather companions and challenge the Demon Kings. When Hamel dies and the remaining party reaches Babel, Vermouth breaks Incarceration's chains with the Moonlight Sword and forces a second bargain: Incarceration returns Hamel's soul, spares Sienna, Anise, and Molon, ends the war, and allows a three-hundred-year grace period while Vermouth restrains Destruction. Incarceration honors that covenant and protects Eugene until the appointed confrontation because he wants to see whether this era can finally produce a different end. (Chapters 24, 349, 546, and 579–581)

War at Babel

Incarceration governs Helmuth during the grace period as an efficient preparation for either victory or the next era. Human-friendly immigration and contracts gather souls without continuous war, while Pandemonium's advanced infrastructure and Babel's forces become weapons for forcing the continent's surrender when the covenant ends. He allows contractors broad freedom and even permits thoughts of rebellion because their ambitions can create valuable unexpected outcomes. His personal attachment remains limited, though Gavid's loyalty and Balzac's final request affect him more than the empire itself; he still intends to reclaim granted dark power and reduce lives to resources if the current era fails. (Chapters 219, 237–239, 524, 577, and 590–593)

When Eugene, Sienna, Molon, Anise, and Kristina enter Babel, Incarceration offers them survival in the next era if they abandon the impossible demand to save both the world and Vermouth. Their refusal makes him the ordeal he believes a genuine answer to Destruction must overcome. He removes the chain restraining his stored power, reveals the memories of his own betrayal, and attacks with the strength, speed, accumulated souls, and corrupted divinity of countless eras. Yet the companions never betray one another or accept despair, and Noir's soul, Balzac's hidden treachery, the Saints, and the wider army create variables that force him to excise much of his own abyss. (Chapters 581–592)

Badly weakened but already convinced by the heroes, Incarceration continues fighting because he enjoys a Hero-and-Demon-King battle that his first life denied him. He reclaims dark power from his army, asks Eugene to show a victory that closes the next era, and finally accepts defeat when the light breaks his remaining chains. He then spends days containing Destruction and guides the party into its core. After Destruction dies, Incarceration uses a final contract to bind Vermouth's independent soul, declines to enslave him, and willingly dies so his now-powerless body can become Vermouth's vessel. His final choice ends both his title and the cycle he maintained. (Chapters 592–594 and 595–613)

Appearance and personality

Incarceration appears as an adult man with black hair, a calm face, and an overwhelming presence, usually framed by the chains that form his cloak, wings, or throne. His eyes often look dull or remote, reflecting attention directed toward spans of time far beyond the immediate scene. He can also manifest only an eye or a body made from darkness when appearing at a distance. Memories of his heroic youth show a younger figure with abundant divine power and an expression defined by despair rather than the bored composure of the Greater Demon King. (Chapters 237–238, 546, 580–586, and 613)

He is patient, formal, curious, and almost impossible to provoke through ordinary threats. Eternity has trained him to treat war, government, contracts, and even apocalypse as recurring procedures. He respects effort and unusual ambition, allows subordinates freedom to pursue their goals, and genuinely admires Eugene's growth or Balzac's successful deception. That respect does not make him benevolent: he starts wars, harvests souls, reads contractors' minds, and destroys servants once they cease to serve his plan, all without claiming that necessity absolves him. (Chapters 219, 237, 546, 581–593)

Incarceration's defining emotion is exhausted despair disciplined into compromise. Betrayal taught him to expect conviction to collapse under fear, so Eugene's loyal companions fascinate and unsettle him. He wants proof strong enough to justify risking the final end of the cycle, but his repeated tests also protect him from placing hope in another failure. Once defeated, he admits jealousy and pleasure rather than pretending pure detachment. His willingness to die and give Vermouth a vessel is not sudden redemption; it is the chosen conclusion of someone whose dreadful purpose has finally been fulfilled. (Chapters 583, 586–594, and 612–613)

Abilities and powers

Incarceration combines corrupted divine power, immense dark power accumulated across successive worlds, dominion over contracts and souls, physical and magical mastery, and the chains that embody his title. He is functionally immortal while the first chain to Destruction remains intact and can overpower Eugene's entire divine party at once. His greatest limitations come from that same bond, the poison and madness sealed within his abyss, and his refusal to lose the identity required to build another era.

Chains, imprisonment, and immortality

Incarceration's first chain binds him to Destruction. It prevents Destruction from killing him, but also prevents Incarceration from killing Destruction, while innumerable linked chains grind through his soul as an eternal curse. As long as the original connection remains, even wounds that destroy his organs cannot kill him. The chains can become a throne, cloak, wings, shields, spears, restraints, or a medium for pulling and redirecting bodies and power. They can stop divine weapons, bind souls and memories, and impose a separate flow on space that frustrates even Sienna's Absolute Decree. (Chapters 312, 372–373, 515, 533, and 583–593)

The chain system is also his method of self-control. Incarceration locks unbearable memories, accumulated souls, divine power, poison, and madness inside an abyss within himself. Removing the central restraint releases his full reserves and speed, but loosening too much Corpse Poison risks destroying his ego and turning him into a mindless calamity resembling Destruction. Chains can be severed, corroded, copied, or shattered by sufficiently strong divine and magical attacks. Balzac's soul also forces Incarceration to excise contaminated portions of the abyss, preserving the original chain at the price of the power needed to continue fighting. (Chapters 562 and 584–593)

Dark power, abyss, and regeneration

Incarceration possesses dark power dense enough to corrupt space into a separate world, extinguish divine light, suppress Eugene's sanctuary, and isolate the Hero from his Saints and Incarnation. He uses it as blasts, barriers, lightning-like strikes, remote phenomena, and a source of regeneration. His abyss holds souls gathered from destroyed eras, the remains of those he killed or commanded, corrupted divine power from his heroic origin, and Corpse Poison distilled from countless deaths. When fully released, these reserves grant speed and force that the heroes initially cannot perceive or answer. (Chapters 583–590)

His reserves are vast rather than inexhaustible. Full power spends life-force and dark power originally saved to create the next era. Severe divine wounds, dream-reality, soul power, Balzac's internal attack, and the need to purge contamination slow his regeneration until immortality only keeps a ruined body alive. In desperation he can reclaim dark power granted to demonfolk and kill them from within, but this recovery is small compared with what he has lost. His final defeat occurs when damage and changed conviction leave him unable and unwilling to keep the cycle's reserves intact. (Chapters 587–594)

Martial, magical, and temporal mastery

Eternity gives Incarceration mastery of weapons, magic, and close combat even though he most often fights with bare hands and chains. His punches shatter sanctuary barriers, divine weapons, and layered defenses; his speed can remove Molon's throat or pierce Sienna before Eugene begins activating Ignition. He reads openings in several attackers simultaneously, deflects trajectories, redirects spatial flow, and can drain control or strength through contact. His experience lets him identify unfamiliar divine, magical, and Demoneye effects quickly rather than relying on one fixed combat pattern. (Chapters 582–590)

At full release, Incarceration compresses action into moments that seem to stop time and attacks before opponents can perceive a trajectory. This is overwhelming but not permanently unanswerable. Eugene's victory divinity adapts to the intended point of impact, Molon shares those heightened senses, and the companions' linked roles remove openings Incarceration would exploit against isolated opponents. Releasing greater poison and madness raises his force further, yet he must reseal them before his reason collapses. His maximum combat state is therefore bounded by identity, stored reserves, and the coordinated resistance he is trying to test. (Chapters 586–592)

Contracts, souls, and world renewal

Incarceration can form covenants in exchange for souls, grant dark power and abilities, read the minds of contracted black wizards, preserve or retrieve the dead, and reclaim what he has bestowed. His pacts with Vermouth demonstrate that the exact terms and a participant's will matter: he preserves Hamel's soul and later binds Vermouth only after Vermouth identifies as an independent person who wants to live. A contracted soul would ordinarily become his vassal or remain under his control, but he deliberately releases that authority at death. (Chapters 219, 546, 579–581, and 612–613)

On the scale of an era, he releases incarcerated souls, restores lifeforce circulation, raises land, and converts remnants into dark power, primal spirits, and mana for a new world. Helmuth's contracts and immigrant policy feed this system by mortgaging human souls, while his knowledge from prior civilizations supports Pandemonium's advanced technology. World renewal follows Destruction rather than preventing it and costs countless individual identities and lives. Once Eugene kills Destruction, Incarceration declares there is no next era to build and chooses death instead of using the machinery again. (Chapters 587, 590, 593, 613, and 621)

Power progression

Relationships

• Eugene Lionheart: Incarceration recognizes Eugene as the strongest Hero he has encountered and protects his growth under the covenant until their appointed battle. He offers Eugene a place in the next era, then uses his full power to test the refusal. Eugene's victory proves that hope, companionship, and unpredictable growth can break the compromise Incarceration treated as inevitable. (Chapters 238–239, 546, and 581–594)
• Vermouth Lionheart: Vermouth's resemblance to Destruction's original self disturbs Incarceration, but his independent will creates the first genuine chance to end the cycle. Their two covenants produce the heroes and grace period, and their final contract preserves Vermouth without making him a vassal. Incarceration gives him his body and wishes him the life he chose. (Chapters 546–548, 579–581, and 612–613)
• Demon King of Destruction: Destruction was once Incarceration's dearest friend, whose betrayal and limitless consumption transformed him into a calamity. Their first chain makes them mutually unable to kill each other. Incarceration rebuilds worlds after its repeated attacks, then holds it long enough for Eugene's party to achieve the death he has awaited across eras. (Chapters 586–587 and 595–613)
• Gavid Lindman: Gavid is Incarceration's Blade and most devoted knight. Incarceration favors him, preserves his life during the first assault on Babel, and permits him a final duel with Eugene, but never shares the whole truth of the cycle. Gavid's last wish that his lord reach the desired end becomes one of Incarceration's few personal attachments. (Chapters 233–239, 524, 539–545, and 590)
• Balzac Ludbeth: Balzac is a contracted wizard whose apparent loyalty hides a plan Incarceration fails to detect. After death, his divided soul infiltrates and consumes the abyss, forcing Incarceration to tear away a fatal portion of his own reserves. Incarceration responds with sincere admiration for a deception that helps protect the current era. (Chapters 219, 573–578, and 590–592)
• Sienna Merdein: Sienna's Absolute Decree, soul power, and use of Noir's Demoneye create laws capable of interfering with Incarceration's ancient power. He still redirects her imposed outcomes and repeatedly overwhelms her, but her analysis and dream-reality are essential to exhausting the reserves that made him seem unreachable. (Chapters 562 and 583–592)
• Molon Ruhr: Molon is the vanguard of both challenges to Babel. Incarceration can destroy his body many times, yet Molon's refusal to remain down and his resonance with Eugene repeatedly force openings. That loyalty directly contradicts the betrayal on which Incarceration's expectations of heroes are founded. (Chapters 233–239 and 581–594)
• Noir Giabella: Noir serves Incarceration without worshiping him and ultimately assists Eugene from within the Demoneye of Fantasy. Her dream-reality exposes his memories and absorbs Corpse Poison long enough for the heroes to press him, making her posthumous loyalty to Hamel another variable beyond Incarceration's control. (Chapters 524, 549–568, and 584–592)

Items

• Chains of Incarceration: Incarceration's chains are physical weapons, soul restraints, defensive armor, and the structure that binds his memories, abyss, contracts, and immortal connection to Destruction. Their strength reflects his stored power, but divine force, the Moonlight Sword, Sienna's magic, and Eugene's final victory can sever or shatter them. (Chapters 312, 372–373, 396, 515, 533, and 583–594)