The Legend of the Blade of Stars

A long, long time ago, when the world was still young and Humans and Elf/Elves were living together in harmony the gods decided to bestow a gift upon them. It was an item like none the world had ever seen, or is ever likely to see a longsword made of a metal so pure that it was nicknamed the Blade of Stars.
It was a poisoned chalice.
Having seen this great weapon, the Humans and Elf/Elves both sought to claim it as their own. From seeing it on display, their best craftspeople worked tirelessly to replicate it's design but to this day none have managed to recreate its sheer beauty or the deadly sharpness of its edges. The continent was divided in chaos, the first of the Great Wars that eventually lead to the continent spliting and these dark times to be upon us.
After seeing the destruction that their gift had brought, the gods told took the blade and told their chosen one, Emyr Seren, to hide it in a place where no mortal or imortal would ever be able to see it again. 
The old legends, shrouded by the mists of time, tell us that he took the blade to the top of the highest hill on the continent and plundged it deep into the rock. The gods helped to hide it my covering the tallest peaks in mist eternal. True to his word, no one has ever seen the sword again.