Zangetsu

Zangetsu has worn several shapes over Ichigo's life. It first appeared as an outsized katana with a flame-patterned bronze guard and red-wrapped hilt, a bloated blade born from borrowed power rather than skill. Once released it settled into its constant Shikai form, a huge cleaver in the mold of a khyber knife with no proper guard or handle, just a cloth-bound tang, its black blade edged in silver and never sealing back into an ordinary sword.

Its true form, uncovered far later, splits into two solid black blades: a large one shaped like the old cleaver with a hollow channel along its spine, and a shorter trench-knife companion with an enclosed guard. The greater blade embodies Ichigo's inner Hollow while the smaller carries his Quincy inheritance, and he binds both hilts in cloth, slinging the long blade across his back and the short one at his hip.

Its defining technique is the Getsuga Tenshō, a crescent-shaped wave of compressed spiritual energy hurled from the edge of the blade at the instant of a slash. Wielding the twin blades, Ichigo can merge a Getsuga fired from each into the cross-shaped Getsuga Jūjishō, powerful enough to scatter Vollständig-tier Quincy attacks. He can also call either blade back to his grip from a distance, as though tugging an unseen chain.

In Bankai as Tensa Zangetsu the weapon compresses rather than enlarges, and its Getsuga Tenshō turns golden and vastly more destructive, forceful enough to split a Yhwach fortified by the Soul King clean in two.

The sword's story mirrors Ichigo's own growth. His first blade sprang from spiritual energy siphoned through Rukia Kuchiki rather than from himself, which made it fragile enough for Byakuya Kuchiki to shear away and Kisuke Urahara to reduce to a stump, pushing Ichigo to learn its name and release its Shikai. Its outline shifted again once his Fullbring left faint traces on it.

Only during the war with the Quincy did Ōetsu Nimaiya reveal that Ichigo had never truly held a proper Zanpakutō, then reforge the weapon from a genuine Asauchi. At that point Ichigo finally reached the suppressed dual-bladed form that had belonged to him all along, its Bankai reshaped to match.