The Vanished Pantheon

The Vanished Pantheon comprises the twenty gods of Ancient Sela who left the people to fight the forces of the Darkness.

The Gods
The Vanished Pantheon [I don't love that name] includes two deities from the Pathfinder Chronicles (simply because Desna and Calistria were named before the transition of the campaign from 3.5E to 5E) and mostly deities from Fifth Edition sourcebooks (such as Torm, Lolth, Gruumsh, etc.).

In the period of time after the departure of the gods, it became known that the gods instituted beings named Stewards as regents in their absence. These Stewards, beings of immense power, soon gained the moniker 'demi-gods'. On the continent of Erinyūl, the Steward of Calistria, then a woman named Tilu, taught the elves a forbidden secret of great power, which resulted in the formation of the Duskblades among the elves. Soon, however, the secret passed to humankind... [more history to be written later. As I write this, I discover so many holes to be filled. There will be major changes to the history later].

On the continent of Korohl, the Steward of Calistria successfully persuaded the fey entities of the sea to save a majority of the continent's population by inviting them to flee to and live on the sea. The Darkness could not penetrate past the power of the sea. The people that stayed on the waters became the Neezo, while the majority of peoples returned to dwell on the land.

Other continents of Sela dealt with the Darkness in different and curious ways.