You must search the world for a being capable of restoring the power to the Fragment of the Dragon's Eye. The only information you possess about such a being is that they exist.
A fragment of the shattered medallion is all that I can offer.
You must find another of dragon blood willing to assist you in forging a new key. Once you secure this key, you must travel to the Wyrmbog in Dustwallow Marsh. It is there that you will find her lair, [player].
Where to find other flights willing to help? Sadly, I do not know... They are said to exist. Some may even work and live among us, disguised as one of the humanoid races. I wish you luck.