Source: People of the Sands, pg(s). 24f.
The living monoliths are said to have been first imbued with life by the sphinxes, the divine guardians of Osirion. Although the first living monoliths were statues raised to a semblance of life, most contemporary living monoliths are mortals who willingly take up the role of immortal warriors through ritual and devotion. To become a living monolith, a being must be an experienced warrior; knowledgeable about architecture, history, and religion; speak the language of the sphinxes; and have a valuable stone scarab called a Ka stone handcrafted and bound to his forehead. The tight bond with this Ka stone gives the living monolith powerful defenses, an affinity to stone, the power to summon sphinxes and demand truthful answers in the name of the rulers of Osirion, and eventually become immortal by living out his life as a living statue.