Muramasa (Zanpakutō spirit)

Tall and lean with sickly pale skin, Muramasa frames his face with shaggy dark-brown hair, two locks crossing over his nose, and turquoise eyes rimmed by jagged purple ovals. A long white coat trimmed in thick fur drapes his frame, fastened at the throat by a purple ascot and a ruby brooch, with a broad striped sash at the waist, pointed boots, and purple manacles that clack whenever his long-nailed fingers curl.

The Hollows he absorbs slowly devour him from within, and his body registers the toll. His eyes weep blood in the early stages, then glaze over red entirely; at his worst he sickens, weakens, and even turns partly transparent, his form failing as the borrowed power eats him alive.

Poised, courteous, and silver-tongued even toward his enemies, Muramasa plays the liberator, preaching that the age of Shinigami lording over their blades is ending and that the spirits will rule instead. It is a performance. His true aim is to reach Genryūsai Shigekuni Yamamoto's mind and seize his spirit Ryūjin Jakka, and the entire rebellion is staged to that end; once the pretense drops he grows cold, even feeding his own followers to Ryūjin Jakka's flames. Beneath all of it lies a single wound: devotion to Kōga Kuchiki, the master he served faithfully for centuries.

Long ago he propped Kōga up, praising him, urging him to seize power and forge a new world, and insisting their strength flowed from mutual trust. As Kōga slid into madness and turned abusive, their bond frayed until Muramasa could no longer hear him, yet the spirit swears he would have come at a single word and spent years laboring to free him. Kōga repays that loyalty by stabbing him, then by snapping his sealed sword and declaring him worthless, which finally breaks Muramasa and drowns him in despair. Only in defeat, hearing Ichigo Kurosaki's voice reach him at last, does he taste the connection he always craved.

As the spirit of a monstrously strong Shinigami, Muramasa carries immense reiryoku that unsettled even a Bankai-ready Ichigo, and he traded even blows with him across three separate fights. From it he spins invisible spiritual threads, tipped with hands, to bind or throttle, though they show up in reflections and vanish if his focus slips; he also warps a target's five senses with illusions, dredging up their own memories to torment them or spawning doubles in combat. A one-handed master swordsman of great speed, strength, and cunning, he can also teleport as green light between realms.

His defining art draws a Shinigami's Zanpakutō spirit out and bends it to his will, snapping the stability between the two and forcing the spirit's negative emotions loose; a victim so robbed cannot manage Bankai until the spirit returns, and a spirit killed by anyone but its owner shatters and dies. Cut off from a living master, he sustains himself by devouring Hollows, storing them inside to summon later and ripping open jagged Garganta at will. When Kōga's rejection breaks him, the swallowed Hollows fuse him into a horrific Hollow hybrid clad in bone armor, capable of high-speed regeneration, Cero, Bala, and vastly amplified speed and power.