Well, so far, so good. I've got a Legionairre from one of Bune's hordes embedded in the matrix of the crystal now. In addition, there's the physical link to Tezcatlipoca through the skull's mask. As a result Ive been having interesting dreams, and I've visited the realms of the Aztec Underworld.
Shockingly, as you may imagine, the dreams have been about... death. Not mine, but Death his own self, ye Grim Reaper has been wandering the dream realms with me. I haven't done anything particularly lucid or purposed in the dreams yet, but I'm happy with the results so far.
The end goal here is to have a talisman so potent from its associated entities that anyone who touches it, regardless of their training, has an immediate ability to communicate with the dead. I don't know how this will manifest with any individuals, since everyone seems to have a unique way of working with things like this, but I imagine tarot, iching, divinations, crystal scryers, and clairvoyants would all have their abilities heightened. I haven't done anything with it to contact a specific dead person yet, but it's on my list of things to do.
For now, I'm still performing conjurations, empowerments, and spending time each day tuning the crystal to the appropriate harmonies of the underworld.