Telltale Doll
A small porcelain doll of unremarkable, androgynous appearance, with Starmetal filigree traced along the inside of its body, out of sight. When a bit of hair, Blood or a fingernail clipping is placed within the small compartment where its heart ought to be, it will change to mimic the appearance of the donor. It will also imitate any injuries they suffer, and upon their death, will shatter. Should the donor step Outside Fate, the doll will lose its connection and be rendered inert until the donor returns to donate once more.
These dolls were based on artifacts designed at the beginning of the existence of the Exalted, which allowed the Incarnae to monitor the health of their Exalts as they warred with the mighty Primordials. They fell out of favour as the Celestial Exalted began to maneuver against each other, and had become rare by the Golden Age, even before the devastation of the Usurpation.
Source: Adapted/expanded from original by Arbane the Terrible on RPG.net