Nuria Natal is a theocratic magocracy with a Titanic leyline running down the Nuria (Nile).
Sounds Egypt-esque to me. I would also play up the technology flavor.
It occurs to me, the technocrats (physicians, pyramid builders, elephant raisers, beer makers, gem makers) built respectable tombs to secure their afterlife. On the walls of these tombs, they depicted and described what they did in life, so as to continue their prestigious skills in the afterlife. Importantly, these murals often explain
how they did things, like how they made glass, or how they made beer, or how they circumcised men.
For D&D purposes, some of the advanced knowledge would often only be obtainable by visiting a tomb. It is a good hook for an adventure.
Note there were no undead mummies in Ancient Egypt. This is a modern popculture invention relating to Frankenstein and Dracula, inspired by Egyptian antiquities.
For D&D themes, maybe treat the undead tropes moreso as a visit to the afterlife, in the underworld (Duat), more like Shadowfell. The Egyptians gods are there in the underworld too, helping the deceased spirit to make the dangerous journey into the underworld. The wellbeing and the opulence of the afterlife in the underworld depends on the funerary monument and items that they prepared while alive, and the magical upkeep by the living. The tombs are thresholds between this world and the underworld, and the spirits can venture back and forth.
Because semen was understood to be a source of life, and because the earth is male, masculine virility and potency is a central symbol for surviving in the afterlife.
Essentially, the spirit leaves the physical body, journeys to the underworld, and there is given a new eternal body. The spirit actually comprises separate aspects, and only those spirits who successfully reintegrate all of their aspects, are able to influence the afterlife, and even to visit this world to help loved ones or exact vengeance.
