Wait for Magus Ariden Dusktower to enfuse the energies of Karazhan into the key.
With the power of the Pendant of Ardan, and the items you have obtained I will begin to channel the energies of Karazhan into the dormant key. With familiar energies it should break the magical seal upon the lock and grant entrance. I will need some time to concentrate, so please, give me a moment to work the complicated magic.
Yes?
The key has been reforged with the magic that once created it, now with it in our grasp we can strike hard at the evil that lurks within that long forgotten crypt.
!?