Well, if you have read the first book - When Doorways Open in the Mythlande Series, then you have discovered a De'thyr.
What does this toothy image represent?
It is the symbol of a Mala Coire type of magical power; it represents the Soul Klaw Essences. The fangs are the symbol for the De'thyr Naka.
What Can De'thyrs do?
These magic users can manipulate/animate the dead so they become one of the unliving. De'thyr's strengths are death and killing. These Skrachers also perform the Kho Shahd ritual that can turn a Thre'shyr into an obedient zombie-like slave. Kho Shahd can open teleportation doorways. De'thyrs can turn a graveyard into an army, a deceased pet into a vicious killer, rotting roadkill into assassins. They speak the language of death, and the dead hears their call.
Are they called anything else?
The Fae calls this group the Draen Mog (Death's Call).
What is the color for the De'thyr Essence?
Their Essense color is Black with flecks of dull colors.
There are eight different Klaw Essences, and each one is represented by a Naka. De'thyrs are just one of the eight. The Opposite of a De'thyr is Li'fyr, and they use the Hona Coire version of the Soul Essences. Li'fyrs can bring inanimate objects to life.
Does anyone recall the name of the round disk used in the Kho Shahd ritual?
Head Imagination Miscreant, HIM