A demigod refers to anybody with divine ancestry. Demigods usually inherit some small degree of the perfection of their parents, they tend to be more attractive, more physically capable, more resistant to disease and injury, to heal quicker and age more slowly. They often also tend to have a psychological pre-disposition towards their god's aspects, the descendant of a thunder god for instance may enjoy being out in storms.
Demigods also may be favored by their divine parent, who might take it upon themselves to aid in their life or set them to tasks they wish to see accomplished. They however possess no real supernatural abilities beyond their innate remarkableness.
In ancient times to be taken as a god's lover was a great privilege and the gods bestowed a gift upon those they slept with, imbuing them with health and longevity. Some degree of this persists in their children. After having sex with a demigod a person will heal more rapidly for about two days, as well as not aging or becoming sick in that period. While this can be a great gift from a demigod lover to their lover or spouse and even has led to some demigod couples being effectively immortal rumors persist of those who pay highly for captured demigods to use them forcibly in order to stay young forever.
Today demigod genes are erratic like other supernatural genes. Usually activating only once every three of four generations. The chances of any of your direct family also being an active demigod is astronomically small, but it possible for a grandparent or great grandparent to be. There's also a decent chance that twins, both fraternal and identical will share the trait if one has it.
Demigods much like Faeborn, Angelborn, and Demonborn can be either latent, passive or active.
Latents are effectively entirely human, but there is a chance that at some point in their adult lift the latent genes will activate and they will become either active or passive. Passives are mostly human but they have some degree of the resistance to disease and aging and tend to be more attractive and capable. They also have the effects of prolonging the life of their sexual partners.
Actives are passives until around the end of puberty, usually seventeen to nineteen, when they activate. They also sometimes activate later in life, although this is very rare in people not living near the Gate. As well as the effects of passive demigods actives also gain other amazing supernatural powers.