Zangetsu (Zanpakutō spirit)

Ichigo grew a split personality of his Hollow self in himself. This Hollow self is his evil alter ego, a commonality of most Hollows.

His overall appearance is practically the opposite of Ichigo, especially in his clothings. While Ichigo wears a black standard shinigami uniforms, his Hollow self wears a white shinigami uniform with black cloth belts. His skin and hair are also fully white.. His eyes are black (on contrary to humans' white eyes) with yellow iris. His white color has led the creation of his fan-name: Shirosaki (a play on his white color, Ichigo's last name being Kurosaki, kuro meaning black and shiro meaning white). It is notable that originally the Hollow self was seen with black teeth, but this changed later to white.

He also has his own version of Zangetsu: On contrary to Ichigo's black cleaver with silver edge wrapped in white cloths, his Zangetsu is silver with black blades and black wrapping cloths. His voice is the same as Ichigo's, except that it is very heavily distorted and also much more lunatic in tone.

Perhaps his most distinguishing feature is his maniacal laughter and lunatic grins. He is brutal and sadistic, his only reason for existance being to take over Ichigo's power and his body to use it to kill everything he sees. He taunts Ichigo as being weak and unsuitable for being a counterpart of, though he relishes the idea of taking Ichigo's powers for himself.

He is seen to be much more powerful than Ichigo, overpowering Ichigo very easily. He is able to deflect Ichigo's Getsuga Tenshō with only one hand, and his Getsuga is incomparably more powerful than Ichigo's. He also gains any ability that Ichigo learns: He can use Bankai and Getsuga Tenshō, albeit in his own version. He can also take over Ichigo's body in battle, in which case a mask starts forming on Ichigo's left side of the face and the eyes blacken. He is able to ignore most of the injuries Ichigo has sustained till the point, and starts fighting like a berserker (much as he does when battling Ichigo in his inner world) with fearsome strength and speed, much more than Ichigo's already abnormal levels.