Mifune

Mifune is Muramasa's Inner Hollow, and an "ally" in his story in Kingdom Hearts: Arcana. In all other story modes, however, he either does not appear or is a minor character; the exception being that he is an optional boss battle in Zane's story.

Origin
Because Sengo Muramasa existed as a spirit for decades before arriving in Soul Society -- without Soul Burial -- he went through a very gradual process of Hollowfication. As a result, Muramasa developed his Hollow and Soul Reaper powers simultaneously.

Soul Society
During a training battle between Sengo Muramasa and Kenpachi Zaraki, the former first unleashed his Inner Hollow, a mask suddenly forming over his face. This dramatically increased Muramasa's Spiritual Pressure, speed, and power to the point that Kenpachi had to remove his eye patch to keep up. The battle was eventually considered a draw. Since then, Muramasa put particular focus on training with his mask and drawing out his Inner Hollow, with whom he later was able to reach a mutually-agreeable arrangement. Ten years after the mask appeared, Muramasa achieved Bankai in a mental training session with Mifune, making it the earliest bankai achieved without artificial means.

Kingdom Hearts: Arcana
When Nathaniel Koroshiya suddenly vanishes from Soul Society, Muramasa embarks on a mission to find him and confirm his status as either deceased, defected, or simply AWOL. Though originally restricted to Karakura Town, Hueco Mundo, and Soul Society, Mifune was able to open Corridors of Darkness and found that, in his Resureccion form, these pathways could be traversed without risk of corruption.

Appearance
Mifune bears a slight, but noticeable resemblance to the Espada Grimmjow, though not quite as muscular and with a hairstyle similar to Vanitas. Unlike Ichigo's Inner Hollow, Mifune is not an albino, having dark hair and - strangely - green eyes. While not ivory, his skin is, however, pale.

Mifune also distinguishes himself from Muramasa through his attire, wearing a black longcoat with the kanji for "Royal Knight" on the back, a blood-red shirt under it, black dress pants, and sneakers. While Muramasa's Zanpakuto is a wakizashi on the right side of his waist, Mifune's form of it is a kodachi strapped to his back. (Note that while the sealed states of the weapon are different, the Shikai and Bankai forms are identical aside from a color change.)

Personality
Like Muramasa and Sen Yosamu, Mifune is honest to the point of brutality, though unlike them, is much more erratic than either. Mifune is reckless, though far from foolish, and once described himself as "subtle as a train wreck"... which tends to be rather accurate. He is also similar to Kenpachi Zaraki, in that he values challenge in combat more than almost anything else, and demands to "stretch his legs" when Muramasa is faced with a potentially powerful enemy.

Sengo Muramasa
Mifune acknowledges Muramasa as the dominant consciousness, though his compliance depends on being given control on occasion, particularly when a challenging opponent presents itself. In exchange for "being let out to exercise" from time to time, Mifune provides valuable insight and an alternate perspective on Muramasa's problems, decisions, and orders, as well as granting instant access to his Hollow Powers on-request.

Sen Yosamu
Sen Yosamu is the spirit of Muramasa's Zanpakuto, and therefore, the two share the latter's mindscape. Neither of the duo attempts to supress or overpower the other, though they aren't exactly friends, either - Yosamu's no-nonsense attitude and unfeeling nature perpetually clash with Mifune's somewhat erratic personality.

Powers and Abilities
Master Swordsmanship Specialist: Being Muramasa's Inner Hollow, his swordsmanship is equal in skill, though he likes to focus more on crushing his enemies with power than on accuracy.


 * Sōkensōin (双剣掃引, Double Sword Sweep): A technique which entails two strikes of a sword of extreme force and speed. The two cuts are made so quickly the target only perceives one swing. Mifune's variant relies on using two swords to achieve the same effect.

Sonido: Mifune, being a Hollow, much prefers using this technique, though he is technically also capable of using a Soul Reaper's Flash Steps.

Tremendous Strength: Mifune is, in terms of brute physical strength, among the most powerful entities Muramasa has ever encountered, known to have once blocked Sephiroth's "Meteor" spell with one hand... and then he threw it back.

Enhanced Durability: There's an urban legend that Kenpachi Zaraki and Mifune had a contest to see who was more powerful. Kenpachi took off his eyepatch and tried to cut Mifune's exposed skin during the latter's Bankai... and Kenpachi's sword allegedly bounced off.

Immense Spiritual Power: Mifune has access to all of Muramasa's vast spiritual energy, and due to the nature of the dual consciousness, a bit more than that. His spiritual energy fluctuates from black to dark purple to ice blue.

Zanpakutō
Sen Yosamu (千夜寒, One Thousand Cold Nights): Its sealed state takes the form of an unmarked kodachi with a small, circular guard, and the hilt is bound in brown leather. The scabbard is black and unmarked.

The Inner World mainly consists of a seemingly endless frozen plane, although there are massive glaciers in the distance. It is eternal night, similar to Antarctica in the winter, although the Southern Lights are particularly vibrant.


 * Shikai: Its release command is "Encase the heart in frozen terror." (冷凍恐怖で包む心, Reitō kyōfu de tsutsumu kokoro) In this form, it takes a form which is like a fusion of Yamato and Lucifer from Devil May Cry 4. It is clearly a sword, although it's designed more like Lucifer. Mifune's version of the blade is dark blue with white lines across it, similar to cracks in a field of ice.
 * Shikai Special Ability: Sen Yosamu's primary and most well-known ability is ____ (Freezing Aura), the name of which is fairly obvious. Sen Yosamu, while in shikai form, has a special property that gradually absorbs all heat within a given radius, generally around 50 feet, and the closer an object is to the blade, the more rapidly its temperature decreases. When used on sentient things, including Hollows, Soul Reapers, and humans, the blade has another, similar power that activates in the same time and in the same way, inducing fear and doubt. Kenpachi Zaraki, Genryusai Yamamoto, and Sosuke Aizen are thus far the only three people shown to be completely immune to this second effect, while the other Captains, along with Ichigo Kurosaki, Naomi Reed, and Nathaniel Koroshiya also have either great resistance or near-total immunity as well. Flintlass, being the manifested spirit of a Zanpakuto, is unaffected.
 * Kōrisetsudan no Ken (氷切断の剣, Piercing Ice Blade, lit. Sword of Ice-Cutting): Sen Yosamu's cold-inducing aura effect is ten times more powerful through direct contact withe the sharp edge via cutting. Mifune's favorite method of victory is to impale his enemy in the head with Sen Yosamu, freezing them from the inside-out beginning with the brain, and then slicing through the (now) ice statue, shattering it.


 * Bankai: Eien no Mōfubuki no Sen Yosamu (永遠の猛吹雪の千夜寒, Endless Whiteout of One Thousand Cold Nights): Mifune brings the shikai form of his weapon to his side, holding it in the same stance as Sora does his Keyblade for the "Duel Stance" Reaction Command in Kingdom Hearts II. Then, he shifts the sword and impales himself in the chest with it as he says "Bankai". The self-impaling is a symbol of absolute resolve and unwavering conviction -- when Mifune summons his Bankai, he intends to emerge either victorious or dead. Unlike Muramasa, Mifune's appearance does not change anywhere near as drastically as the former's; instead, the Bankai weapon simply inverts the color scheme of his attire. For weaponry, Mifune summons a black longsword made of ice-energy for his left hand, and his right arm is covered in ice armor, ending in a powerful gauntlet.
 * Bankai Special Ability: Kami Hachi-tō no Kyodaina Ryū (神八頭の巨大な竜, Eight-Headed Dragon, lit. Eight-Headed Monstrous Dragon God) Mifune's Spirit Pressure aura manifests as an enormous dragon with eight heads. He usually starts his Bankai by just using melee attacks, although he then will immediately activate this ability. Each of the eight heads is an extension of Mifune's own consciousness, meaning that he has access to eight added perspectives should he need them, and can control them with his will. Mifune can move while using this abiltiy, but controlling all eight dragon heads requires so much concentration that he can't form his weapons for melee combat, so he has to use at least one or two heads for defense in order to protect himself. Also, partly due to his Hollow nature, in Mifune's version of this attack, the dragon heads take on a much more monstrous appearance, and are pitch-black rather than ice-blue.

Hollow Powers
Being the Hollow half of a Vizard, Mifune's mastery over his Hollow powers is vastly superior to his Soul Reaper powers.

Basic Powers
When Mifune is dominant, he doesn't need the mask, since he is a Hollow himself. Due to this, Mifune has a natural advantage in strength, speed, and durability against most opponents, and he has a low-level healing factor as well. Mifune is also a master of the Cero technique, and has a special variant which he calls Cero Final (Final Zero), which takes five seconds to prepare, though is ten times more powerful than his regular Cero. Mifune is also capable of creating up to three illusory doppelgangers of himself, which he uses to distract his opponents and catch them off-guard.

Resureccion
The command for Resureccion is, "Devoramos" ("We Devour"). This triggers a metamorphosis into Mifune's Full Hollow Form. In this form, he resembles a Paladin from Mideival Europe, wearing armor of ebony and gold, though the front of his helmet is in the shape of Muramasa's Hollow Mask. In this state, if Mifune is also using his Zanpakuto in it's Shikai or Bankai forms, then the colors of the sword are inverted (compared to his version). In Resureccion, Mifune's physical abilities are enhanced fourfold what they previously were, his already incredible strength and speed in particular.

Theme
Mifune's theme song is "Symphony of Destruction", by Megadeth, which he sometimes will quote during battle or when trying to make a point.