The people of Skyss worship a pantheon of gods that they know exist. Those gods at times manifest themselves and have been known to inter-breed with mortals. Mostly those are in the ancient sagas, but demi-gods and heroes with lineage from the main pantheon demonstrably exist. The Skyssian Creation Story is called The Mother's Dream.
I've not created an entire pantheon, I've simply used a handful of handy gods and goddesses, so this list isn't exhaustive. There are 9 gods in the Skyssian pantheon (and more in other pantheons). These gods are real. People have met them when they manifest (not so recently, they tend not to manifest except under extreme conditions - all the pantheons have made tacit agreements to largely stay out of the affairs of men, other than to offer advice and to work through priests).
When Gods or Goddesses breed with humans the offspring are demi-gods, and always of the same gender of the divine parent. Demi-gods have very long life spans, and inherit some of the powers of their divine parent. They aren’t immortal, but they tend not to get ill, and live for a very long time unless they are killed. Some have become Gods in their own right, but not of the Nine. According to the old legends the Goddesses who choose to bear demi-gods do so within a day of the liaison, several have been left with their mortal father to grow up in the world.
Offspring of Demi-gods and humans are Heroes. Anyone with 1/16th divine blood is classed as a Hero. Heroes tend to marry into the nobility or other Heroes. They have extended lifespans by human standards, and tend to be immune to most diseases. Depending on their lineage, and how far removed they are from the original divine coupling, they may heal faster or be able to call on the powers of the Gods & Goddesses that they are descended from. It is not the number of connections that count, but rather the strength of the connections.