When Shu's children, Geb and Nut, desired to have children of their own, Ra learned that one of those children would seize his throne. He decreed that Nut could not bear children on any of 360 days in a year. When Nut managed to thwart Ra, he charged Shu with keeping his own children apart as their eternal punishment.
In Egyptian mythology, Shu (meaning emptiness and he who rises up) is one of the primordial gods, a personification of air, one of the Ennead of Heliopolis.
Shu's grandchildren are Osiris, Isis, Set and Nephthys.
As the air, Shu was considered to be cooling, and thus calming and pacifying. Due to the association with air, calm, and thus Ma'at (truth, justice and order), Shu was portrayed in art as wearing an ostrich feather. Shu was seen with between one and four feathers.
Shu holds up Nut while Geb is resting on the ground.
Although Shu does not formally appear, Nut explains his duty to Sadie Kane and the story behind it. He sends a wind to repulse the goddess when she demonstratively attempts to visit her husband. Shu later sends another wind to tear apart a starry image of Nut that had been sent to Geb as a gift in a letter
When Anubis and Sadie talk at the school dance, they get interrupted by Shu, Anubis' great-grandfather, who is sent to keep the two apart. Shu is disgusted by Anubis' display of affection towards a mortal which is forbidden without a human host and chides him, revealing to Sadie that Anubis is actually a child in god standards when she tells him off for it. Anubis tries telling Sadie about Walt's idea, but he is too late and Shu blows them apart. Then, Leonid comes with the aid of Shu, telling Sadie he needs her help.
When Carter calls for the gods to help fight Apophis, Shu is one of the gods that responds and helps fight Apophis until Carter and Sadie destroy him. When the battle is over, Shu leaves Earth with all of the other gods except Anubis. According to Anubis as he is now in a mortal body, Shu won't interfere with his relationship with Sadie, but he thinks Shu will continue to watch over him which he and Sadie joke about.
He is Anubis' chaperone and is disgusted by his relationship with Sadie and enforces the ban on him not seeing her again. However, this may simply be because Anubis has no mortal form which is the only way a god and a mortal can be together. Notably, Shu doesn't intervene when Anubis goes to take Walt as a host and is there for several minutes in the presence of Sadie against the rules. As Anubis was there to take a host and got permission from Walt to do so, he may have allowed it even though Anubis didn't immediately merge with Walt.
Shu also has a tendency to chastise Anubis and treat him like a child despite him being over 5,000 years old. When Sadie points this out to him, Shu says that Anubis is a child by god standards, revealing the source of Anubis' young appearance and personality.
Despite his apparent disgust towards mortals, Shu transports Leonid, who has secretly learned to channel his powers, to Sadie. However, he seemed to think he did enough to help afterwards by doing that much.
Being one of the primordial gods, he is extremely powerful. He is more powerful then either of his children, being able to hold them apart for millions of years
- Aerokinesis: As the god of air, he has absolute control of air. He can manipulate air currents and fly. He can generate and control wind.
In The Serpent's Shadow , after meeting the Kanes , Leonid realized that they aren't evil like Sarah Jacobi makes them out to be and interested in the Path of the Gods, begins secretly learning how to channel the power of Shu as he has always been a good air elementalist . Leonid succeeds in learning the path of Shu on his own . After Leonid witnessing Jacobi and her lieutenant Kwai communicating with various monsters including Apophis himself, Leonid flees St. Petersburg, contacting Shu and convincing him to transport him to Sadie Kane in Brooklyn.
Shu is Anubis' chaperone and great-grandfather and treats him like a child and is extremely disdainful of his relationship with Sadie. When Sadie tells him off for treating Anubis like a child as he's 5,000 years old, Shu brushes it off as, according to him, that is a child in god standards. Shu separates Anubis from Sadie, informing him of the ban on him seeing Sadie again and drags him away. Despite this, Shu doesn't intervene when Anubis enters Sadie's presence to see about taking Walt as a host and doesn't stop him even though he is in her presence for several minutes with no host. This may be because Anubis was about to take a host at which time it would be acceptable for Anubis to be with her despite any dislike Shu had. After Anubis merges with Walt and wants to dance with Sadie again, she asks him if Shu will interfere like last time. Anubis explains that as he is now mortal, Shu won't, but believes Shu will still keep an eye on him which he and Sadie joke about.
- Sadie refers to him as the "fussy aviator god," referring to his preferred appearance of a pilot. She also calls him the god of hot air.
- His Greco-Roman equivalent is Aeolus.