Cocytus

Name: Cocytus

Gender: Male

Role: Fifth Floor Guardian of the Great Tomb of Nazarick (Floor of Glacier)

Race Levels: Insect Fighter 10, Vermin Lord 10, others unknown

Class Levels: Sword Saint 10, Asura 5, Knight of Niflheim 5, others unknown

Base Level: 100 (Race 30 + Class 70)

Alignment: Neutral (Karma Value: 50)

Creator: Warrior Takemikazuchi

Title/Epithet: Ruler of the Frozen River

Residence: Fifth Floor – Great White Orb (Snowball Earth)

First Language Style: Harsh, distorted voice in which only kanji are normal and everything else would be rendered as hard-edged phonetic “blocks” (described in the original work as “lumps of sound forced into the shape of a voice”)

Voice Actor (Anime): Kenta Miyake

Cocytus serves as the floor guardian responsible for the defense and management of the Fifth Floor, a vast frozen glacier region within the Great Tomb of Nazarick.

He was created by the player Warrior Takemikazuchi and embodies his creator’s concept of a pure “martial warrior.”

Despite his monstrous appearance, Cocytus is one of the more honorable and fair-minded beings in Nazarick, especially toward warriors who show courage and resolve.

He is also deeply loyal to Ainz Ooal Gown, and even fantasizes about serving as a “grandfatherly retainer” to Ainz’s future heir.

Within Nazarick’s internal hierarchy, he stands alongside Albedo and Sebas Tian in overall combat power and is ranked third among the floor guardians for distinctive combat specialties.

As a weapon specialist in particular, he is considered Nazarick’s number one in pure weapon-based offense.

Cocytus is built around the concept of a stoic martial artist: disciplined, grave, and utterly devoted to combat honor.

He respects strength and courage, and even when facing enemies far weaker than himself, he recognizes and honors those who stand before him with true warrior resolve.

Unlike many other denizens of Nazarick who casually look down on humans and other “lesser” races, Cocytus treats worthy fighters as fellow warriors regardless of species or status.

This honorable attitude later helps him win the trust of the lizardman tribes when he is assigned to govern their settlements on behalf of Nazarick.

His sense of respect is shown clearly during the Kingdom invasion when he confronts Brain Unglaus.

Recognizing Brain as a warrior who has accepted death and stands his ground, Cocytus treats him with dignity, orders Brain’s corpse preserved in ice out of respect after defeating him, and deliberately chooses another route to the castle so as not to trample over the path Brain had defended.

At the same time, Cocytus shares Nazarick’s trademark eccentricities.

He is obsessed with the idea of Ainz Ooal Gown having an heir and dreams of serving that child as a devoted “old retainer,” to the point that he can lose track of his surroundings when he slips into these delusions.

Because of this tendency to daydream, he is not entirely in a position to criticize the constant, often ugly rivalry between Albedo and Shalltear Bloodfallen over who will become Ainz’s official spouse.

Still, his basic demeanor remains far more sober and straight-edged than most of the other guardians.

One unexpected trait he inherited from his creator is a sharp sense for naming things.

When Nazarick evolves into a full-fledged nation and a formal title for Ainz is needed, Cocytus proposes calling him the “Sorcerer King,” literally “the king who guides magic,” a suggestion that is enthusiastically accepted by the others.

Interestingly, he gets along very well with Demiurge, despite their opposite temperaments: Cocytus is simple, direct, and martial, while Demiurge is cunning, sadistic, and overwhelmingly intellectual.

Their unlikely friendship is one of the more charming oddities in the internal relationships of Nazarick.

Cocytus resembles a giant light-blue insect standing upright at about 2.5 meters tall.

His form combines the visual impression of a mantis and an ant, reshaped into a bipedal warrior’s silhouette.

His entire body is covered in an icy, chitinous exoskeleton that constantly exudes cold air.

Along his back, body surface, and tail stretch numerous sharp spikes that resemble icicles, emphasizing his connection to frost and his Fifth Floor domain.

His “mouth” area features a large, insect-like lower jaw, adding to his intimidating, alien visage.

Despite his armored, almost knight-like silhouette, he does not actually wear conventional armor: his carapace itself counts as external equipment, which has mechanical implications for his defenses.

Cocytus possesses four arms, each capable of wielding a different weapon simultaneously.

In battle, he often carries a massive katana, a silver halberd, a broadsword, and a mace, turning him into a walking storm of blades and bludgeons.

Cocytus is among Nazarick’s top-tier front-line combatants and is explicitly described as the strongest weapon combatant among the floor guardians.

His specialty is close-quarters weapon fighting, and his raw offensive power in melee is said to rival, and in that field surpass, other guardians.

In overall combat stature, he stands on the same tier as Albedo and Sebas Tian.

However, his build is heavily skewed toward offense rather than defense or magic, making him a glassier cannon compared to some of his peers.

He has excellent tactical insight at the battlefield level.

In terms of reading opponents, understanding weapons, and making immediate combat judgments, his observational ability even surpasses Albedo’s as a warrior.

He is highly knowledgeable about armaments and can identify the weapons of all the “Forty-One Supreme Beings” (the original guild members of Ainz Ooal Gown).

He owns 21 different weapons himself, though in major battles he usually focuses on a core set of legendary gear.

His weakest areas are magic potency and strategic-level thinking.

His mana pool and magic attack power are described as relatively low compared to dedicated spellcasters, and he originally lacked broad strategic foresight.

This strategic weakness becomes apparent in his first campaign against the lizardmen, where he suffers a painful defeat despite his overwhelming individual strength.

However, Cocytus learns from this failure, takes strategy and long-term planning more seriously, and grows significantly—earning Ainz’s satisfaction for his improvement.

In later volumes, his expertise in weapon use and close combat training is recognized formally.

Ainz appoints him as an instructor to teach Ainz himself advanced weapon-based combat techniques and melee fundamentals.

By the time of volume 15, Cocytus has also become a trainer for Pandora’s Actor and Narberal Gamma.

He additionally plays a role in the management, organization, and training of the Sorcerer Kingdom’s military forces, which include both undead troops and living demi-human and human soldiers.

Cocytus is primarily a physical combatant, but he does possess several cold-themed and utility abilities:

Ice Pillar

A spell of unknown tier that causes a single pillar of ice to erupt from the ground per casting.

It can be used for direct impalement or terrain control.

Piercing Icicle

A spell of unknown tier that allows Cocytus to fire dozens of sharp, arm-sized icicles from his hand.

It is a ranged ice attack and, in the web novel version, is referred to as “Piercing Ice Pillar.”

Frost Aura (Knight of Niflheim Class Skill)

A class-based aura that deals continuous cold damage to nearby enemies and slightly slows their movements.

The range and strength of the aura can be adjusted depending on the situation.

Wind Slash

Used in the drama CD “The Sealed Evil Tree.”

Cocytus employs this technique to slice off two 300-meter-long tentacles of the evil tree Zaitlukwae, indicating tremendous cutting power, though the precise mechanics are not detailed.

Kurikara Sword

Also seen in “The Sealed Evil Tree” drama CD as one of two attack methods under the technique “Immovable Wisdom King Strike.”

Its power increases the more negative the enemy’s karma value is, making it especially devastating against evil foes.

Macabre Smite Frostburn

Another attack from the drama CD, used to sever two of Zaitlukwae’s tentacles.

Details are limited, but it clearly combines devastating physical force with frost damage.

Rasetsu

A skill from the drama CD that appears to target multiple enemies at once.

It likely functions as a multi-target offensive technique.

Attack Nullification (provisional name)

A skill that negates attacks from weapons imbued with weak magic for a set duration.

This dramatically raises his survivability against low-tier enchanted weapons.

Perception of Directed Attention (provisional name)

A sensory ability that lets Cocytus detect when others focus their attention or emotions on him.

In the story, he uses this to recognize Albedo’s surge of furious emotion directed his way.

Combined with his already extraordinary physical might and weapon mastery, these skills make Cocytus devastating in close-range battle, especially against opponents who rely on conventional melee or low-tier magic.

His cold-based attacks, auras, and terrain manipulation further reinforce his role as the absolute ruler of the Fifth Floor’s frozen environment.

Cocytus is closely associated with powerful legendary weapons, many of which reflect the martial tastes of his creator:

Divine Katana “Zanshin Tohko” (God-Tier Item)

A mythic-grade katana with a blade longer than 180 centimeters.

Originally owned by Warrior Takemikazuchi, it was given to Cocytus upon the creator’s “retirement,” and Cocytus treasures and frequently wields it.

Silver Halberd “Beheading Fang”

A white-silver halberd that Cocytus often carries as a default weapon.

The anime frequently depicts him wielding this halberd, likely due to its striking visual appearance.

Broadsword

A heavy one-handed sword suitable for brutal slashing and chopping.

Specific details are not provided, but it forms part of Cocytus’s standard four-weapon configuration.

Mace

A blunt weapon emphasizing crushing damage, ideal for opponents resistant to slashing or piercing.

As with the broadsword, details are sparse, but it complements his arsenal with varied damage types.

In combat, Cocytus typically equips four weapons at once, one in each of his four hands.

His combination of multiple legendary weapons, diverse damage types, and god-tier armament allows him to unleash overwhelming offense in close quarters.

One of his core weaknesses, however, is that his chitinous body counts as an “outer shell” in game terms, preventing him from equipping conventional armor pieces over it.

No matter how much he invests in fortifying his exoskeleton, he can never reach the same defensive heights as heavily armored guardians like Shalltear Bloodfallen or Albedo.

This limitation leaves him comparatively weaker in defense despite his high level.

It also means that specialists in hit-and-run melee, such as Sebas Tian, are especially dangerous opponents for him.

Cocytus’s combat style is that of a relentless martial powerhouse.

He charges into the front lines, leveraging his four arms to create an inescapable zone of lethal steel, supplemented by cold damage and debilitating ice magic.

His tactical sense is excellent at the scale of individual battles.

He can read opponents’ movements, analyze their equipment, and adapt his weapon choice and techniques with impressive speed.

By contrast, his strategic thinking—the ability to plan campaigns or consider political and logistical ramifications—was initially underdeveloped.

This flaw is dramatized in his first campaign against the lizardmen, where he underestimates their unity, environment, and morale, leading to a serious defeat.

Ainz, however, uses this failure as a teaching opportunity rather than a reason for punishment.

Cocytus internalizes the lessons, begins to think beyond individual duels, and matures into a more well-rounded leader and commander.

His later role as an instructor for Ainz, Pandora’s Actor, and Narberal Gamma further reinforces his evolution from “mere warrior” into a guiding martial figure for Nazarick’s elite.

In the Sorcerer Kingdom era, he takes on duties overseeing training, discipline, and tactical readiness for mixed forces of undead and living troops.

Relationship with Ainz Ooal Gown

Cocytus’s loyalty to Ainz Ooal Gown is absolute and shaped by both respect and admiration.

He sees Ainz as an ideal overlord and the rightful master of Nazarick, placing his trust in Ainz’s judgment even when he personally fails.

His fantasy of serving Ainz’s future child as a loyal “old retainer” reveals a surprisingly sentimental and almost domestic side to his otherwise martial personality.

This dream drives his intense desire to see Ainz produce an heir, occasionally distracting him from reality when he indulges in these mental scenarios.

Relationship with Other Guardians

Cocytus maintains a fundamentally respectful stance toward his fellow guardians.

He willingly acknowledges their strengths: Albedo’s defenses and command ability, Shalltear Bloodfallen’s power, Sebas Tian’s lethal melee prowess, and others.

He is particularly close to Demiurge, forming an odd but strong friendship.

Where Demiurge is an intellectual schemer who takes pleasure in cruelty, Cocytus is straightforward and honorable, yet somehow their differences complement each other.

He also shares a surprisingly high karma value compared to many of Nazarick’s residents.

Among the guardians and important NPCs, he is surpassed only by characters such as Sebas Tian, Pestonya Shortcake Wanko, Yuri Alpha, and CZ2128 Delta in moral inclination.

Even so, Cocytus does not hesitate to carry out brutal or lethal orders when they serve Nazarick’s interests.

His sense of honor is shaped by warrior ethics rather than modern human morality, and he sees no contradiction in showing respect to enemies he is about to kill.

Fifth Floor and the Great White Orb

Cocytus rules over the Fifth Floor of Nazarick, an immense glacial field marked by deadly cold and treacherous ice.

At the heart of this domain lies the Great White Orb, also known as “Snowball Earth,” a gigantic sphere that functions as a central structure and focal point of defense.

The Fifth Floor’s environment naturally complements Cocytus’s frost-based abilities and his own cold-emitting body.

Anyone entering his domain must contend not only with his direct might, but also with environmental hazards and frost-aligned monsters under his command.

Frost Virgin (Snow Woman)

Cocytus’s primary named subordinate is the Frost Virgin, sometimes described as a snow woman.

She is an ice-element monster of level 82, dressed entirely in white, with pale bluish skin and long black hair in the original descriptions.

Her canonical illustration did not appear in the novels initially; her visual design was first shown in the anime, where her hair appears closer to gray than pure black.

Her main duty is to guard the Great White Orb on the Fifth Floor.

The Frost Virgin is stationed within one of the enormous crystals surrounding the Great White Orb.

She remains inside this crystal structure when not actively engaged, acting as a dormant but potent defensive measure.

Her most notable trait is extremely high detection and perception ability.

She is capable of seeing through Ainz’s high-level invisibility spells, indicating that her perception and anti-stealth abilities are of an extraordinarily high tier.

Under Cocytus’s command, she serves as both a guardian and a living detection system for intruders on the Fifth Floor.

Her existence further solidifies Cocytus’s floor as one of the most dangerous and tightly controlled sectors of Nazarick.