Ancient Sword of Imbria

Appearance: The Ancient Swords of Imbria are of a very peculiar make, they are both thick and wide bladed, being very strong and durable blades. The blades are all decorated with baroque patterns and inlays in the flat of the blade, some of which are very intricate. This is easier considering the average Imbrian sword is roughly 3 inches wide. The swords have between 30 inch and 36 inch long blades, and are much lighter than they appear.

They are made from a metal that can only be found on the Moon, and since the destruction of Imbria there are no more mines working to produce this metal. Despite the size and thickness of the blade, they are easily wielded with one hand. The swords do not have crossguards or quillons and are ill-suited to sword on sword fighting. 

In the past, attempts have been made to melt down and reforge items made of 'moon metal' but these have all failed as the metal once heated to melting will quickly begin to evaporate into a gas wherein it is lost. The secrets of forging and shaping moon metal were lost with Imbria.

The Forges of the Moon: The Ancient Swords of Imbria were named such as the swords were old and had been well used long before the lunar kingdom was brought to it's full power. These swords were mostly forged in the smokeless flames of the city of Crysia, back when that city was a meeting place for mercenaries, knight errants, and other adventurers-upon-return. The swords were not forged for the fighting of man against man, but were instead made for the hunting and slaying the wild and horrific beasts that dwelt in the deep and dark places of the Moon. Often, these brave warriors would go hunting at night, when the sky was only lit by Earthlight and stars, armed with heavy blades to face and destroy those wicked and forgotten creatures.

Crysia was destroyed in the Harrowing of the Moon, and there is nothing left of that place but a glassy blackened sea of stone.

The Deeds of The Past: The Ancient Swords of Imbria are old weapons, and once, each blade told a story. The story was written on the blade itself in a mix of artwork and the whorling Lunar script. While there are a few of these swords that survived the destruction of Imbria and the desolation of the Moon, there are no knights or families left who know the history of the blades. Perhaps even more sadly, there are few if any people, scholar or sage, who recognize that the artistic decoration on the surviving blades are actually a form of written language.

Specifics: 

The Ancient Swords are made of Moon Metal (which henceforth shall be called Moonsteel) which is roughly 1/6th the weight of regular steel and is just as strong and durable. The swords are slightly oversized, but they were intended for beast and monster slaying, not sword on sword combat. They are single edged, and can stand up to a good deal of abuse. 

Ancient Swords can be used as spell casting items, functioning in a similar fashion to a rod or a wand. This is true for almost any item made of moonsteel.

The swords deal double damage against evil and dark aspected creatures, and triple damage against flame and heat aspected creatures. If a critical is scored, the sword is subject to a breaking check (since moonsteel rather dislikes intense heat) and if it fails, the sword breaks off in the creature. It will continue inflicting damage as the metal boils away inside said monster. If a second critical is scored, the blade explodes inside said creature for lots and lots of likely terminal damage.

Ancient Swords on Earth are rare (there might be 6 total)