Shinsō

Shinsō (神鎗, lit. God Spear) is a finely crafted katana made especially for Hisaya. Made of an unknown metal, the blade is ebony black and, according to the person who passed it onto her, it is said that she never has to sharpen it, its edge eternally kept sharp by some unknown means. True, the woman has yet to brush its edge against a whetstone and only needed to clean it every once in a while.

Abilities
Known as a sword that never dulls, Shinsō is capable of cutting through almost anything with little to no difficulty. It can withstand clashing against Kaguya bones, which are said to be harder than steel, and Kōton-based weapons, not gaining a dent or getting chipped. The owner assumed that it is made from Kōton metal, though has yet to prove this since she lost contact with its craftsman.

Its metal proved its durability because of its capability to absorb the woman's Scorch Release properties. While most metals would become soft and brittle upon introduction of extreme heat, Shinsō remains resilient and still retains its sharpness. This allows Hisaya to use the katana in slashing and cutting while also threatening its targets to become desiccated bodies once hit.

Hisaya assumed that her sword's abilities stopped there, but was soon left surprised when it revealed another hidden ability. Shinsō can extend at high speeds and can be used to impale targets from a distance; it should be noted that it carries tremendous force when it extends, meaning it can easily push back anything in its way. The female can keep the blade extended and swing it around in wide arcs, enabling her to attack multiple targets quickly and simultaneously. The blade itself glows a bright white when it increases its length. Hisaya claims that Shinsō can extend a hundred times its original length at maximum, which opted her to give it its nickname of Hyapponzashi (百本差し, lit. Hundred-span)

Trivia

 * Some concepts are inspired by Gin Ichimaru's same named Zanpakutō.