Hihiirokane

Hihiirokane (究極の金属) is the end-point of evolution for Magisteel, a material only heard of in myths and fables. It's an ultimate metal with a performance of top-of-the-line Legend-Grade at the bare minimum, with it possessing the capability to evolve into God-Grade under the right conditions.

Appearance
Hihiirokane, when not in use, has a pitch-black appearance due to it not allowing any light to reflect off of it. When wielded by a user that it accepts, however, the metal reveals its true colors of a vibrant silver-steel that shines with a rainbow light.

Characteristics
Hihiirokane, as a material that is naturally close to God-Grade, possesses a will of its own, a "Tool Spirit (付喪神)" that allows it to choose its owner. This possession of a Tool Spirit allows Hihiirokane to remain immutable when faced with damage or the passage of time, being able to heal any and all damage with the consumption of Magicules, and even holding onto its elemental attribute indefinitely. The Tool Spirit will naturally block all wavelengths that attempt to touch it when not in use, including light-waves and the prying eyes of Analytical Appraisal, with even Ramiris's Small World being unable to analyze it when it's in this state.

When the Tool Spirit does recognize a suitable wielder, it allows them to synchronize their magical force with it and unleash its true power, which, when unleashed, reveals a terrifying performance capable of potentially fighting against wielders of Ultimate Skills in the right hands. It also allows the user to temporarily transcend their flesh and achieve a status similar to a fully incarnated and transformed Spiritual Lifeform, with temporary magic bodies being stabilized and capable of remaining in the material world indefinitely, and Material Bodies temporarily achieving a state close to divinity, albeit with great strain.

As the ultimate version of Magisteel, Hihiirokane naturally has the ability to change its shape to match an accepted user's desires completely, being able to change appearance as well as equipment type—from a sword to a spear, from a spear to armor, etc—freely at the user's discretion. It is also possible to transform it into something innocuous such as a necklace or bracelet to further conceal its existence to those around them.

Equipment

 * Albert's Spirit Sword & Armor
 * Benimaru's Crimson Lotus
 * Gabiru's Vortex Spear
 * Gazel's Straight Sword
 * Rimuru's Drago Blade
 * Shion's Divine Hercules Edge
 * Tear's Tear Scythe
 * Three Great Generals Garb

Body Structure

 * Beretta's Body
 * Carrera's Skeleton
 * Testarossa's Skeleton
 * Ultima's Skeleton
 * Zegion's Exoskeleton
 * Zelanus's Exoskeleton