In ancient times there was a highly advanced race which learned how to harvest power from the lust and desires of living creatures.This knowledge allowed them to reach the pinnacle of their prosperity and create all sorts of wonders and artifacts.
But this golden age saw an end, there are many theories about what happened to them but no one really knows, some say it was an incurable disease that drove their race to extinction. Others believe that their absolute power corrupted them, and their civilization collapsed leading to massive wars exterminated all of them.
While few hold the belief that an unknown entity or force killed all of them, and is now hiding in the depths of the planet, the most fanatic believers of this created a religion based on worshipping this entity, which they call "The Great One".Now the only things that remain about them are legends and ruins.
Its fairly know among adventurers that there are ancient wonders and artifacts still hidden in the world, forgotten to the passage of time and waiting for some brave hero to uncover them and wield the strength that they possess.
But its also known that these items reside in dangerous places, where traps and monsters are plentiful and a lot of strength, courage, and bravery is required to reach said treasures.