She of the origin, she of the primal crack, she of the boiling beginning, she of the riddle, she keeps me here, toiling and toiling – Anne Sexton
They had been watching, waiting, guarding for a millennia, hoping against hope that the Beast would not arise on this watch. Thousands of years they had been watching, guarding the Key from the ones that sought to destroy it, to use it for their own ends and destroy the balance between dimensions. Regimes came and went, countries and powers rose and fell, and still they waited; and as carefully and closely as they watched, the monks were still caught unaware.
The Beast had been consigned to this dimension, chained, restrained and subject to the limitations of humanity, captured within a frail form, unable to wield its powers upon and within the Terran dimension. And still, they knew it was not a fail-safe, that eventually the Beast could overpower and sublimate the human host.
So they had begun forming a plan, a way of safeguarding the Key from the clutches of the latest threat. Seeking out guardians for the Key proved difficult, made further impossible by the strength of the Beast. In their search for a guardian, a champion, the elders of the order had stumbled upon the legends of the Chosen One. In time, they had discovered more than legends, they had managed to locate the Chosen One. Unfortunately for them, before they could introduce this One to the Key, she was killed by one of her foes. Her executioner, for that was what the foe was, intrigued some of the elders, given the ferocity of their battle.
Intrigued as the elders were, they had decided to investigate this new warrior. His history, as it was recorded, listed numerous battles against other Chosen Ones, defeating and outright killing two, damaging others. Never once had this warrior shied from battling the Chosen Ones, seeking out one after another, forcing battles and confrontations, never once backing down from a fight. The elders had decided to follow the path of this warrior, while seeking out the newly Chosen One. The next few proved less than able, despite their chosen status.
Time was slipping past too quickly, and the Beast was getting stronger, breaking through the human form to exert its control. Events had fallen in that the dark warrior had been hampered, neutered by demon hunters intent on forcing their will onto demonkind and now worked, albeit reluctantly with the current Chosen One. Working rapidly, concentrating, the monks began weaving the web of protection to shield the Key from the Beast. Using material at hand, the monks forged a substance and form for the Key.
And, like a cuckoo in the nest, the Key took shape and was transplanted into the fabric of the life of the current Chosen One . . . the Vampire Slayer, Buffy Summers.