Beyond his role as the god who separates earth from sky, later Egyptian religious texts developed a further chapter of Shu's story in which he takes an active turn on the throne itself. According to material preserved chiefly in New Kingdom and later ritual papyri, when the aging sun god Ra grows weary of ruling over gods and men and withdraws to travel the sky in his solar barque, he hands earthly kingship to his son Shu, who reigns for a time as king of the gods on earth, continuing the work of maintaining cosmic order that Ra had begun.
Shu's reign is not peaceful: the same hostile forces of chaos associated with the serpent Apep are said to rise against him, and after enduring conflict and hardship as king, Shu in turn grows weary and ascends to join Ra in the sky, passing rule down to his own son Geb, who becomes king in his place, before the succession continues on through Osiris and eventually to Horus. This chain casts the standard genealogy of the Heliopolitan Ennead, Ra to Shu to Geb to Osiris to Horus, not merely as a family tree but as a literal sequence of divine kingships, each ruler in turn wearying of the burdens of rule and passing them to the next generation, a theological pattern that mirrors and validates the succession of human pharaohs, each king understood as inheriting an office that stretches back through Horus and the Ennead to the very reign of the sun god himself. The sources for Shu's own kingship are fragmentary and appear relatively late in Egyptian religious history, so the episode is best treated as one strand of temple theology's elaboration on the older core myth rather than a complete, continuously attested narrative.