Any information on the Vikings and related would be very helpful for this idea.
After the settling of the Vikings on Iceland, a blacksmith who had settled there with them in Iceland had created three anomalous swords in 839 A.D. using Icelandic magical staves.
Long ago, each sword used to grant the wielder significant influence and power, enough to allow them to reach high-ranks in any hierarchy and achieve control over societies/organizations. Should multiple people declare shared ownership of a sword, they will experience hostility towards one another and will attempt to take the sword for themselves.
Other properties include unusually high resilience, sharpness and penetrative ability along with the ability to shift sizes. A strong attraction to the swords also occurs when observing them, with this effect being stronger when the viewer knows of the swords' anomalous properties.
For centuries, the swords continued to be taken and used by other civilizations that managed to retrieve them, though all three were never brought together.
Later after the Auctoritas Impertus formed, a high-ranking individual affiliated with the Auctoritas Impertus, known only as "Archibald", was sent to Iceland from Buchau after the Auctoritas Impertus caught word of the swords and their creator.
There, he approaches the deceased blacksmith's abandoned house, where he finds his diary. The diary contains along with an entry in the diary describes a certain day where he was visited by a "strange, unusually friendly man who looked like someone's thrall." The man spoke about his swords, and what they allowed the Vikings to do.
Before leaving, the man said "Those swords being so great, I think they will live forever" and had shook the blacksmith's hand afterward, setting a curse on him and his swords. The curse would ensure that his swords would be used for ruthless conquering and enslaving of civilizations, and that his spirit would be forced to watch each act of brutality.
At the end of the diary is a paragraph describing what the blacksmith thought the man meant by his last sentence before he had left. An entry describing a nightmare about conquering/enslaving/slaughtering would also follow.
The blacksmith then realized that his swords would now be a detriment to societies for years to come. For his very last entry, he wrote down his hopes for the swords to be neutralized somehow.
Once Archibald returned to Buchau, he notified the Auctoritas Impertus of the swords and explained his belief that the swords must be retrieved and neutralized.
The swords were retrieved and kept hidden in a catacomb in the Holy Roman Empire. Their solution for the "neutralization" of the swords was to shift the sizes of them to an incredibly large size (to increase weight) and to root them into the ground. They were not actually neutralized, but they were kept firm in place.
Neutralization would not be confirmed until viewers of the swords no longer experienced any sort of attraction to them. Neutralization occurred at the end of the Viking Age and the failure of Harald III to invade England.
Any critique is appreciated.