Amahagane

Amahagane (天鋼, lit. "Heavenly Steel"), also known as the "Sacred Regalia of the Tempestuous Buddha" (激仏の神器, Gekibotoke no Jingi), is an ancient treasure of unimaginable power; it's one of the few Magic Tools that's rightfully classified as a Mysteria Relic — artifacts containing immense power and has an origin that's beyond understanding. It's said to have been crafted for the sole purpose of combating the effects of its counterpart, the Mashogane.

Often represented as the element of Yang (陽, Yō), it's known to bring out the full potential of its chosen wielders; those who can harness its incredibly vast power are dubbed as "Devas" (天全般, Tenzenpan), worshipped as enforcer's of heaven's will and envoy of the gods. Interestingly enough, it's capable of housing the essence of various divinities, regardless of origins, their powers being harnessed at the user's discretion. This gave it another moniker, "Pure Essence of the Heavenly Family" (天族の純気, Tenzoku no Junki).

Currently, there are twelve existing Amahagane, as some have been lost to the passage of time, thus scattered across different lands, worlds, and even dimensions. The only known method of creating one is through the legendary ritual, Taiki Bansei (大器晩成, lit. "Late Maturity of Grand Talents") — performed by either a high-ranked Onmyōji or an Archmage.

Overview
"Legends tell of an artifact that harnesses the power of the god's light, purifying all evil that it shines upon; it's said to contain the essence of the divine and capable of bringing out one's hidden potential, paving a road to greater power. Though many were created during a period of great upheavel, only a few are left in the modern era. Truly a relic from a divine age."

- An Esoterologist reading about the Amahagane in an old text.



Takamagahara
"When one's power is synchronized with the Amahagane, the gem is capable of emitting so powerful that it warps the very dimensions around its bearer, temporarily creating a space that the user is able to unleash their full power. Truly a gift from the gods, a clear sign of their blessing."

- Erza Asakura talking about the Takamagahara.

The Takamagahara (高天原, lit. "Plain of High Heavens") is a special dimension plane that's temporarily created by the Amahagane, harnessing the user's magical power with its own energies.....

Kamigakari
"Do you know why the Amahagane is called the "Pure Essence of the Heavenly Family"? It's because its very makeup allows it to seal the souls of divine entities and harness its powers. Only when one truly understands themselves and the nature of the Amahagane, can they tap into this immeasurable source — calling forth the very wrath of heaven itself."

- Erza Asakura's allusion to the Kamigakari.

In order to harness the deity's power that's locked in an Amahagane, a special technique called the Kamigakari (神憑, lit. "Divine Possession") was invented — existing since the gem's conception.....

Trivia

 * The name of this article was chosen by a randomizer for Japanese weaponry and objects because the author couldn't come up with something proper.
 * This was one of the ideas the author was playing around with during his "hiatus" from the wikia. He decided to employ it because it was based around the from legend, but give it some alterations here and there to make it more "authentic". Also, it was a perfect plot device to use in one of his Heroic Chronicles storylines because it was centered around a parallel dimension that's based on the Sengoku Era of Japan and alludes to two of his characters seen in other storylines, thus doubling as a reason to flesh them out a bit more.