Ichigo's zanpakutō is named Zangetsu, which means "cutting moon." The spirit of Zangetsu appears as a man in his 30s or 40s, and Ichigo refers to him as "old man" (ossan). Zangetsu has also been called the "black-clothed man." He is portrayed as wise and calm, often testing Ichigo in unconventional ways that seem contrary to their stated goals. Zangetsu can temporarily close fatal wounds during combat, though it's unclear if this is a unique ability. Unlike most zanpakuto, Zangetsu has no release command.
The shikai form of Zangetsu looks like an oversized, elegant cleaver without a hilt guard. The sword stands as tall as Ichigo, at 1.74 meters, with a black blade and silver edge. When not in use, the cloth extends to cover the sword and retracts when needed. This cloth can be used to swing the weapon like a flail or toss it at opponents, but this technique is rarely employed.
Zangetsu's bankai, Tensa Zangetsu, meaning "heavenly chained cutting moon," is highly unusual among zanpakutō. Instead of creating a massive creature or effect, Ichigo's bankai shrinks the sword into a daitō with a black blade and a handguard shaped like a manji, representing "ban" or "full." The cloth on the hilt is replaced by a short chain with a broken link, similar to a plus spirit. Additionally, Ichigo's robe changes into a long-sleeved, ankle-length black coat with red lining, resembling Zangetsu's own attire.
In bankai form, when Ichigo enters the zanpakutō realm, Zangetsu appears much younger, around Ichigo's age. Zangetsu's special ability, getsuga tenshō, fires concentrated energy blasts from the tip of the blade in the shape of a crescent moon.
After revealing himself as the manifestation of Ichigo's Quincy powers, Zangetsu admits he initially did not want Ichigo to become a Shinigami, fearing it would expose him to various dangers and ultimately force Zangetsu to kill him. However, after numerous trials, Zangetsu acknowledges Ichigo's growth and perseverance, deciding to support him instead of hindering his progress, eventually relinquishing control over Ichigo willingly.
(Source: Wikipedia)
