Kepher is an innate sixth sense of the Arisen that was formed through the Rite of Return and the massive amount of Sekhem poured into their mummified frames. It allows a Deathless to locate sources of Sekhem in the world, although the means vary (some mummies experience vivid vision, while others are drawn to a source of otherworldy music).
In most cases, Kepher is a refinement of the Sekhem sense that was already present in those workers in the Guilds that were chosen for the Rite. As a result, the pull is mostly directed to Vessels that are affiliated with the Arisens respective Guild. While it is possible to use Kepher to search for other Vessels, it has to be an willful act. Mummies are also able to tell if a person was in contact with a Vessel, making it easy for them to locate tomb-robbers.