Spirit: Hyōrinmaru appears as a tall, young man with long, wild, teal green hair, an icy blue X across the center of his face, and gray eyes. In his human form, Hyōrinmaru appears as a stoic and silent man dressed in loose samurai-like garments a chain around his waist (similar to his Zanpakutō form) and a dull gold adornment on his chest (similar to the design on Hitsugaya's sash). His arms and legs are covered in ice, similar to Tōshirō when using Bankai, and he has a prehensile tail with an icy tip. At any time, Hyōrinmaru can take the form of a gigantic, icy blue, serpentine dragon with large wings and an echoing voice.
Blade Appearance: Hyōrinmaru (氷輪丸, "Ice Ring") When sealed, Hyōrinmaru looks like a normal katana with the exception of the guard, which is in the shape of a four-pointed bronze-colored star. Its hilt is light blue and sheath dark blue. The sheath completely dissolves when he draws his sword. The sword is somewhat longer than most Zanpakutō, at about 1.4 meters long, making it taller than Hitsugaya, preventing him from wearing it at the hip. Instead he carries it on his back by his green sash over his right shoulder. Hitsugaya is one of four people that carry a Zanpakutō on their back, the others being Ichigo Kurosaki, Love Aikawa, and Hiyori Sarugaki.
Hyōrinmaru is the strongest of all ice-element Zanpakutō in Soul Society. As such, Hitsugaya doesn't need water to be present in order for him to use its abilities. Hitsugaya's control over Hyōrinmaru's power has been shown great enough to use any of its Bankai attacks (with less control) with Shikai
The spirit of Hyōrinmaru is that of a gigantic, ice blue, serpentine ice dragon with large wings and an echoing voice. Hitsugaya has had a close connection to his blade since first awakening his Shinigami powers. Before Tōshirō began training to control his Shinigami powers and leaking reiatsu, Hyōrinmaru would constantly appear in his dreams in an icy landscape (most likely Tōshirō's inner world) and call out to him, although Tōshirō was still not able to hear him. Hitsugaya's inner world is seen as an icy landscape easily accessible to him as he enters into a meditative state.
Ability: Shikai: Hyōrinmaru's release command is "Sit Upon the Frozen Heavens" (霜天に坐せ, sōten ni zase; Viz "Reign over the Frosted Heavens"). In its Shikai, Hyōrinmaru extends slightly in length, and gains a crescent-shaped blade attached to its hilt by a long metal chain, which can extend greatly if necessary by force of will. The chain itself can be used as an attack or to entangle a target
Shikai Special Ability: Hyōrinmaru allows Hitsugaya to control water and ice. His slashes create an immense amount of spiritual power which overflows from the tip of the blade, creating a flow of ice shaped like a Chinese dragon. The dragon flies towards opponents and instantly freezes anything it touches. Hyōrinmaru can create multiple ice dragons to attack an opponent from various angles. Hitsugaya can also direct his slashes towards the ground and form a wave of ice which rushes over his opponents, overwhelming and freezing them. The chain-blade also freezes anything Hitsugaya traps with it. The power it expels is so overwhelming that in Soul Society (where Hitsugaya is not placed under a limiter), its mere release affects the weather within the immediate vicinity, creating a thunderstorm or a blizzard
Tensō Jūrin (天相従臨, Subjugation Of The Heavens): One of Hyōrinmaru's basic powers, as well as its strongest. It allows him to control the weather in the immediate vicinity, or more specifically, control the water in the surrounding atmosphere. The ability is usable in both Shikai and Bankai modes. However, Hitsugaya states that this aspect of his powers is not fully mature and that he doesn't like to use it in Bankai mode, as he is unsure of whether or not he could control it and keep it from killing everyone in the vicinity.
Bankai: Daiguren Hyōrinmaru (大紅蓮 氷輪丸, "Grand Crimson Lotus Ice Ring"; Viz "Great Roaring Coldly Shining Moon"): causes ice to flow from Hyōrinmaru onto Hitsugaya, starting at his right arm which ice forms onto in the shape of a dragon's head around his sword hand, encasing the sword up to the hilt; which also changes from the shape of a four-pointed star to that of eight-pointed star. The ice continues forming up over his shoulders with two large wings sprouting from his back and a long tail. The ice forms down his left arm encasing his hand which ends in a claw. Hitsugaya's feet are encased in ice in a similar manner to his left hand which as they to end in claws. These new ice limbs are movable and can be used as an extension of himself to aid in battle. During some appearances of his Bankai, three flowers of ice form floating behind him, each consisting of four purple petals shaped like diamonds. These petals melt away petal by petal as Hitsugaya's battle progresses, leading Shawlong Kūfang to speculate that Hitsugaya's Bankai will fade when all twelve petals disappear, assuming that the captain's Bankai was incomplete due to his young age. During his fight with Luppi, these petals were noticeably absent; however, during his fight with Tia Harribel, they were present once more and they also appeared once again with his fight with Aizen.
Bankai Special Ability: Hyōrinmaru's Bankai has several additional techniques.
Bankai Regeneration: During his battle with Luppi, Hitsugaya's Bankai was damaged. However, it regenerated, and Hitsugaya stated that as long as there is water in the air his Bankai can be revived indefinitely.
Ice Clone: Once per activation of his Bankai, Tōshirō is able to create and shape a large amount of ice into his exact likeness. It is very life-like as it can appear to bleed. It has yet to be revealed the exact circumstances that limit this ability to one use.
Shield of Ice Wings: Hitsugaya is capable of wrapping his wings around himself like a sphere protecting him from any attacks.
Ryūsenka (竜霰花, Dragon Hail Flower): When Hitsugaya stabs his opponents, a huge burst of ice erupts from the point of contact between Hyōrinmaru and the opponents, encasing and freezing them. Hitsugaya can then proceed to shatter the ice and his opponent with it.
Sennen Hyōrō (千年氷牢, Thousand Years' Ice Prison): Hitsugaya creates many ice pillars which encircle him and his enemy. At his command (when he turns his sword 90 degrees counter-clockwise), these pillars then move towards the enemy, enveloping and crushing it. Though this technique is very powerful, Hitsugaya infers that it takes a considerable amount of time to prepare, and therefore the distraction of his enemy is crucial in successfully completing this attack.
Hyōten Hyakkasō (氷天百華葬, Frozen Heaven Hundred Flower Funeral): This ability is an extension of Hyorinmaru's Tensō Jūrin power. However, because Hitsugaya dislikes using Tensō Jūrin while his Bankai is active, he rarely uses it. The ability opens up a huge hole in the clouds through which a large amount of snow falls down on to his opponent. As the snow comes into contact with the opponent, ice flowers sprout all over their body, instantly trapping them in a pillar of ice. Hitsugaya claimed that when the last of the 100 petals falls, the life of the one who touched it will be over.
Guncho Tsurara (群鳥氷柱, Icicle Flock): Hitsugaya can transform water into ice and then swing his Zanpakutō in an arc which fires an array of ice daggers at his target.
Hyōryū Senbi (氷竜旋尾, Ice Dragon Swirling Tail): With this technique, Hitsugaya swings his sword in a linear direction and creates overflowing ice from his blade in the form of a crescent.
Zekku (絶空, Void Sever): This ability allows Hitsugaya to control his Hyouryū Senbi technique and send it up into the air.