Hyo hyo! What a childish provocation! Did you think I, Gyokko, would be undone with such prattle? You seem desperate. It's embarrassing.
Gyokko possesses a notably bizzare physiology, taking on the form of a pale white, abstracted, grotesque humanoid figure with a muscular upper torso that has no arms and resembles that of an armless statue growing from a porcelain vase; similarly to a djinn.
He has multiple infant-like hands that line his back. Gyokko's face is somewhat even more distorted. Large green mouths displace the position of where one would expect eyes, and his actual eyes are located vertically from one another on his face; one eye appearing in the constantly open bottom mouth and the other is seated at the center of his forehead. The kanji for Upper Rank (
In an emergency, Gyokko can molt and transform into his true form, which bears heavy resemblance to that of a merman. In this state, Gyokko retains his facial features and muscular physique but now possesses a more humanoid body covered in transparent scales akin to a fish. Gyokko also grows longer hair, black markings on various places around his body, webbed hands, and a long serpentine tail in place of his legs.
Gyokko is depicted to be short tempered, shallow and arrogant, especially when it comes to things regarding his "art" as seen when he was easily enraged by Muichiro when he began to insult and make fun of the quality of his art and through his conversation with the Hashira, constantly praised himself as "beautiful" and his work even more so, further reinforcing his arrogant and narcissistic personality. His arrogance was most prominently displayed after he was beheaded by Muichiro Tokito, referring to the Mist Hashira as an inferior and lower life form while calling himself a superb and chosen being.
He has also shown himself to be incredibly petty and jealous, as seen when he attacked and mutilated Hotaru Haganezuka due to his jealousy of the latter focus and dedication to his work, surpassing his own zeal when working on his own art and made him want to instead make the latter lose his focus and waste time on the swordsmith due to this petty jealousy.
He is also shown to be incredibly morbid as when Doma told him he placed a human head on top of his pots like a plant, Gyokko immediately saw it as more inspiration for his "art", the extent of this morbid and violent inspiration for his "art" is shown even more when he brutally murdered several swordsmiths and used their corpses to create a "beautiful" piece by stitching their bodies together along with sticking several swords into them, this extreme sadism is shown even further when he built in the feature of them to scream when a sword is shoved deeper into his "artwork" implying that they were still alive.
Gyokko, at the time Managi, lived on the outskirts of a fishing village near the coast, and was disliked for repeatedly collecting fish carcasses and doing other strange things. He lost his parents at an early age (they went out fishing and never came back, their drowned bodies found badly damaged), so the villagers kept their distance, thinking that he had lost his mind. It seemed he became fascinated by the beauty of his parents’ drowned bodies. Some times afterward, Gyokko killed a village child who came to tease him and stuffed the body in a jar. In rage, the child’s parents stabbed Gyokko with a two-pronged fishing fork. He was left to die there (a half-day passed and he was still alive) and Muzan Kibutsuji was passing by, so he turned Gyokko into a demon.
After becoming a demon, he would develop a taste for humans, especially children. He modified his body as he liked and continued to live while sneering at all living things from the bottom of his heart.
Having been summoned to a gathering of the Upper Ranks, Gyokko greeted Akaza, asking him how he was after ninety years and barely hiding his disappointment of the idea of his colleague's survival along this years. The potted Demon also greeted Doma, exchanging small talk about the pot he had given his fellow Upper Rank as a gift. Shortly after this, Gyokko listened as Muzan Kibutsuji informed the group that Gyutaro had died and berated them for their uselessness. The Upper Rank informed his leader that he had information that would get him closer to achieving his goals, only to have his head ripped off due to the information being unconfirmed. He was then ordered to head over with Hantengu once he corrected his mistake, leaving him bemused. The potted Demon was then approached by Doma, who asked him about the information he had and if he could tag along, and was shocked as Akaza destroyed Doma's head from behind.
At the swordsmiths' village, Gyokko devoured an unsuspecting villager and spat him right back out, stating that it wasn't edible. He then noted that destroying the swordsmiths' village would severely weaken the Demon Slayers.
When Muichiro Tokito and the two villagers come upon the shed looking for a new sword, Gyokko ambushes them from a ceramic pot. He introduces himself and asks if Muichiro would like to see his art. He then presents "Death Throes of the Smiths" a morbid piece consisting of multiple swordsmiths' bodies stitched together with swords sticking out of them.
Once attacked by Muichiro, he retreats inside his ceramic pot and reveals he can transport himself from pot to pot at will. He explains that the pots are his pride and artwork, and becomes very upset when they are damaged. He then summons many fish from a pot and uses his Blood Demon Art: Thousand Needle Fish Kill to attack Muichiro, who lets himself be hit. Gyokko wonders what art he should make for Muichiro, but is rebuked and told he is worthless by Tokito. Upset again, he traps Muichiro with his Water Prison Pot technique, commenting that death by suffocation is "stylish and beautiful."
While Muichiro struggles to escape the Water Prison Pot, Gyokko advanced upon the shed. He enters and sees Hotaru Haganezuka working on the blade extracted from the training doll. Hotaru doesn't notice Gyokko's entrance behind him, enraging Gyokko at the prospect of another artist more concentrated on his craft than he. He summons a fish to attack Hotaru, breaking the sword-smith's mask but not his concentration. Hotaru's dedication to the blade incentives Gyokko to force him to break his concentration rather than straight-up murdering him.
Muichiro escapes from the Water Prison Pot with help from Kotetsu, surprising Gyokko and causing him to unleash his Octopus Vase Hell technique. Muichiro's Sea of Clouds and Haze technique nicks Gyokko, and he ducks back into his pot, reappearing in a different pot. He argues with Muichiro about the beauty of his pots, becoming enraged after an insult to their balance, and unleashes his Ten Thousand Gliding Slime-Fish technique. After Muichiro deflects two of his attacks, Gyokko reveals his true form and becomes more serious about killing him. Gyokko's true form has the ability to turn anything he punches into fish, and has heightened speed and strength. Muichiro uses Obscuring Clouds to decapitate Gyokko, much to his disbelief.
Overall Abilities: As the holder of the fifth highest position in the Twelve Kizuki, Gyokko is an extremely powerful demon. His unique Blood Demon Art and techniques allow him to easily outclass the average demons and give him the necessary edge to overwhelm and kill even the Hashira, the most skilled and powerful swordsman in the Demon Slayer Corps. As Upper Rank Five, Gyokko is more powerful than Gyutaro and Daki, the former having killed 15 Hashira and the latter 7. Gyokko has displayed many impressive feats of strength. Most notably, in his duel with Muichiro Tokito, Gyokko was able to overpower and hold the Hashira back for the majority of their fight, even managing to bring him to the brink of death. If not for Gyokko's inherent egotistical nature and Muichiro awakening his Demon Slayer Mark, the Upper Rank would have more than likely been able to kill him.
Flesh Manipulation: Like all demons, Gyokko possesses the ability to manipulate his own flesh to a certain extent. He presumably uses this ability to shift his facial features and adopt his djinn-like physiology. Gyokko also displayed the ability to grow numerous short arms on his head and torso, even while he was decapitated.
Immense Durability: As an Upper Rank, Gyokko possesses an extremely durable body superior to that of Gyutaro, whose neck was nigh-uncuttable by Tanjiro Kamado. His durability was further amplified in his molted form, where Gyokko's skin becomes layered in thick and hard scales that are noted to be harder than diamond, making his body extremely fortified.
Immense Regeneration: Gyokko's regeneration is quite advanced as he is an Upper Rank demon. This was shown when he survived being decapitated by Muzan Kibutsuji and later sealed off the wound and reattached his head. He also displayed the ability to quickly heal injuries inflicted by Nichirin Swords without much difficulty.
Immense Speed & Reflexes: Gyokko is incredibly fast, as shown when he easily evaded Muichiro's attacks and unleashed techniques that the Mist Hashira was barely able to dodge. Furthermore, Gyokko managed to react to a suprise attack by Muichiro who had awakened his Demon Slayer Mark, meaning that his movement speed would have amplified considerably. Even so, Gyokko managed to hold off the marked Hashira for an extended period of time, even managing to move so fast he appeared to teleport and overpower Muichiro briefly using pure speed.
Molting Transformation: In an emergency, Gyokko can molt in and transform into his true form, boosting all his abilities and liberates him from his vase, allowing him to move freely without needing to teleport. Gyokko's true body is extremelly durable as well, since the Upper Rank remarked that the scales that cover his body are harder than diamond. Furthermore, whatever Gyokko touches is transmutated into fish, making him extremely dangerous to fight in close range.
Talented Artist: Due to his obsession with pots, he has gotten quite skilled at painting and making them, so much so that Muzan has taken a keen interest in them and even selling them for a high price, implying that they were made with amazing skill and craftsmanship.
Unlimited Stamina & Endurance: Like all demons, Gyokko possesses infinite stamina and endurance. He first displayed this when being decapitated by Muzan, where the Upper Rank didn't shown any signs of pain, but even commented on how pleasurable it was. Furthermore, Gyokko commented on how having a sword slash his neck was beautiful.
Porcelain Vases: Gyokko's Blood Demon Art revolves around his porcelain vases. He can presumably spawn them anywhere within his vicinity and create multiple pots of varying sizes at once. Gyokko first displayed the ability to freely teleport from one pot to another instantaneously, offsetting his lack of legs and allowing him to travel far distances with minimal effort as well as to evade attacks easily. Gyokko can also trap objects (such as people) inside his pots. If the object he wishes to seal is too big, the pots can simply compress them to fit inside. The pots also seem to give Gyokko liberty of whatever is inside, which he uses to merge the swordsmiths together in impossible ways and allows him to create whatever he pleases inside them.
At the beginning of the Swordsmith Village Arc, Gyokko spawns numerous gigantic fish-like amalgamantions to terrorize the village and kill its inhabitants. They are unable to be killed by regular means and only die when the pots on their back are destroyed. These creatures all possess unique traits and characteristics, some have sharp claws, some have multiple humanoid legs or even monstrous teeth. They also seem to be decently powerful, as these amalgamations can kill the Demon Slayers that were meant to guard to village. However, their strength still pales in comparison to the Hashira, as Mitsuri and Muichiro swiftly subdued these spawns with ease.
Gyokko's Blood Demon Art is notably themed around the sea and aquatic lifeforms, as his techniques are based on summoning non-sentient creatures that resemble fish from his pots. These fish monsters similary possess differing abilities and charateristics. Some of them can shoot out a barrage of poisonous needles at his targets or leave behind dangerous acid once they are killed. He also summoned goldfish-like monsters with scythe-like appendages to threaten Hotaru Haganezuka. Gyokko can also summon giant octopus tentacles from his vases to restrain his enemies or destroy the surroundings. Lastly, Gyokko can also manipulate and create water from his porcelain vases, which he uses to suffocate his targets by trapping them inside a solidified version of the liquid.
- Thousand Needle Fish Kill (
千 本 針 魚 殺Senbonbari Gyosatsu?) - Gyokko summons floating fish demons from his pots which spit out a barrage of poisnous needles. The poison contains paralyzing properties which immobilize the target.
- Water Prison Pot (
水 獄 鉢Suigokubachi?) - Gyokko creates a vase structure made out of water that traps the target. The water suffocates the target and prevents them from using any breathing technique, making it difficult for them to break free and escape.
- Octopus Vase Hell (
蛸 壼 地 獄Takotsubo Jigoku?) - Gyokko manifest gigantic tentacles from his pots to restrain his targets. These tentacles are strong enough to destroy a shed and are noted to be extremely durable.
- Ten Thousand Gliding Slime-Fish (
一 万 滑 空 粘 魚Ichiman Kakkūnengyo?) - Gyokko summons a total ten thousand slime-fish from multiple pots to attack his target and eat them, leaving nothing but bones. When these fishes are cut, their severed bodies will spread a poisonous liquid before they turn to dust. The poison is also percutaneous meaning it can be absorbed through the skin. Once the poison is absorbed, the target presumably dies.
- The name "Gyokko" contains the kanji for "ball, jewel" (玉 gyoku?) and "pot, jar, vase" (壺 ko?).
- Gyokko's human name, Managi (益魚儀), contained the kanji for "benefit", "fish", and "ceremony".
- Gyokko's summoned fish-like Demons are reminiscent of Junji Ito's fish demons from "Gyo."
- Gyokko is Muzan's favorite Upper Rank. His pots are rather beautiful and sell for a high price.
- Gyokko is one of the only Upper Ranks (the other being Nakime) who does not have a back story mentioned in the manga regarding his past or his first meeting with Muzan. However, the second fanbook provides a brief summary of his past as a human.
- Muzan was the only living being that Gyokko didn't hate.
- Only three people, including Muichiro Tokito, have seen Gyokko in his true form.
- (To Muichiro Tokito) "Hyo hyo! What a childish provocation! Did you think I, Gyokko, would be undone with such prattle? You seem desperate. It's embarrassing."