Ishigiri

Will Killer

The famed sword of the great Kamejin Sword-Saint, Takesada Toshio, it is said to have been the deadliest blade in history, responsible for repelling the invasion of armies of Oni and unifying the Abral Islands behind one culture that rejected magic. Now one of the famous nine sacred treasures held by the Hatanaka family, it is displayed with great honor in the royal palace of Kochi.
The name Ishigiri roughly translates to Will Killer, as it has been said that anyone who saw Toshio with this blade had their willpower drained and tried to run, fearing his might.

The Legend of the Blade

Ishigiri is believed to have been forged by the greatest ancient swordsmith in the Abral Archipelago, known as the Faceless Blade. It is said he had no identity, as he put every fragment of his soul into the forging of his swords. Five swords of the Faceless Blade are said to have endured past his death, including Ishigiri.
The Faceless Blade died in a battle against an Oni army, and his blades were scattered, with Ishigiri ending up in the hands of one known as Takesada Toshio. The Sword-Saint.

Takesada Toshio by Jarhed

History's Deadliest Sword

Whether Toshio was the immediate next wielder of Ishigiri after the Faceless Blade, or if he came decades or even centuries after the forgemaster, no one is certain.
There is even contention around him using it for some of his first battles, with some accounts saying he acquired Ishigiri years into his war against the Oni.
Whatever the case, Ishigiri ended up in the hands of a man named Takesada Toshio, who wielded it in bloody wars against enemies said to be as strong as Dragons.
One of the most legendary battles is said to have been Takesada Toshio against a horde of Oni warriors who wielded magic blades, infused with their own powerful spells. During the battle, the Oni grouped up to destroy a large building that held many Tainuki refugees, but Toshio blocked their joint attack with a single swing of Ishigiri. Parrying every single Oni attack and killing the entire opposing army, Toshio and Ishigiri saved the Tainuki.
When Takesada Toshio died, his blade was lost alongside his body. With it, a great mystery began to spread. Where were the remains of the Sword-Saint, and where was his fabled blade?

The Arms Race

Legend spread of the blade, that it had to have had some great enchantment on it, and that if one could wield Ishigiri, they would be able to do anything, just as Toshio had.

The Sword-Saint

Takesada Toshio, better known as the Sword-Saint, is considered the greatest single combatant in history, and the father of all Kamejin swordsmanship.
From an ancient period of history, Toshio's exact lifespan and era is unclear, but he is known to have cleared the Abral Archipelago of the dangerous Oni that lived on its land, causing trouble for Tainuki natives and Kamejin settlers.
Said to have come from Eikō no Shima, or Glory Island, Takesada Toshio managed to rally two divided species across a large chain of islands, uniting them under one shared cultural umbrella.
Though he could not unite them under a single government in his lifetime, the idea of the Abral Empire is one that ultimately traces itself back to Toshio.

The Anti-Mage

Due to the strong magic of the Oni, few had been able to stand up to them, but the Sword-Saint was said to almost repel magic with his very presence, and thus was able to easily stand against the Oni with only his sword, his skill, and his incredible will.
It is said that the willpower of Takesada Toshio was so great that he created a Dead Zone for mana, the largest in the world, where magic could not flourish.
Strong Magic Zones have only been made by Gods or natural phenomena, according to most theories, as have Dead Zones. Toshio is thus the only one to single-handedly affect the flow of mana in an entire region of Totania.
World Court Classification
Praxian

There were many theories as to what the enchantment on it could be. Did the metal used in it somehow repel magic? Did it grant wishes, or boost the strength or speed of its wielder? Would it match its wielders power to that of their opponents? A thousand ideas were pitched, but there was no certainty as it remained lost for centuries.
For hundreds of years, vast amounts of resources were poured into expeditions in search of Ishigiri. A literal arms race, as all the different powers around the Abral Islands combed over every shore, every battlefield, every wave, and every tree to try and find Ishigiri, to no avail. It evaded all searching, and the Kamejin and Tainuki both ended up running in circles around each other trying to discover a weapon that did not seem to have any intention of being found.
It was only discovered in the period immediately following the Sengoku Jidai, when the Hatanaka clan had united the Abral Islands under the Abral Empire, finally fulfilling a dream attributed to Toshio himself. A Hatanaka retainer found Ishigiri, returning it to the Emperor before ever testing it. After all, it should be the Emperor that reveals the awesome power of the deadliest blade. When it was discovered that the Emperor had the blade, an ongoing war to overthrow him ended instantly and the belligerents submitted, saying that him having Ishigiri proved their cause was unfounded and lacked any chance at victory.
The Emperor gathered a crowd and wielded Ishigiri before them, taking it from its hilt for the first time and preparing to use it to execute the leaders of that ill-fated rebellion. This was the blade that would show the legitimacy of the Hatanak dynasty, and as the Emperor swung it... he found no enchantment. The blade cut well, albeit in a rough manner that showed it needed to be sharpened and prepared for combat again, but it was not what anyone expected. The resources spent to find it all amounted in a sword that anyone could get from a blacksmith all over the Abral Empire.
It was sharpened and given to a great samurai during the Age of Heroes, but soon enough that samurai gave the blade back to the Hatanaka family, saying it was best kept with them, since it was old and did nothing that a normal blade did not do. This samurai feared being the one to break Ishigiri, and so refused to use it any longer.
Ever since, Ishigiri has been on display in the Hatanaka palace in the city of Kochi, kept on display but never wielded. Some say the Hatanaka have the greatest warrior of each age swing it once, to prove their worth with the finest of blades. Others say that no one has laid hands on it in hundreds of years.

The Will Killer

Ishigiri is a bronze blade, with a small liner of electrum, and a copper hilt. It is finely crafted, but holds no special power, and its blade has dulled over the years. To those unaware of its history, they may see it as a regular, albeit ancient, sword.
It is given the classifcation of Praxian by the World Court despite having no power, because the World Court believes it still can inspire the same willpower that Takesada Toshio had when he once wielded it, and thus it could be used to great effect by anyone who seeks to cause harm to others with it. The Sword-Saint was a hero, but no one can be certain the next one to fill his shoes will be.
An unimpressive tool that only makes its legendary wielder all the more impressive. It is not any power imbued in it by its swordsmith, wielder, or ally that makes Ishigiri the most deadly blade in history. It is the simple fact that it was wielded by history's greatest combatant, an extension of his very soul as a warrior. The will killer could only work because Takesada Toshio's will was unmatched.