How I Stopped Worrying and Learned to Love Eberron
Mankind is not an old race. There were no humans walking the earth during the Age of Demons. But that age of evil and magic still echoes into the present era, and the tiefling is clearly a product of that connection through time. The ancient magics and rituals of the demon lords passed through the ages, corrupting individuals along the way. But that knowledge rarely touched a large group of people before it destroyed them completely. There are still whispered tales of cities and armies wiped from the earth because of their terrible knowledge. But when this old magic finally reached the human race, it did not repeat those fabled disasters.
Most modern tieflings can trace their roots back to Ohr Kaluun, the island city-states in ancient Sarlona. As the first humans swore blood oaths and gave live sacrifices to the rakshasa rajahs, they set themselves on the road to fundamental change as a people. Over the centuries, their bodies changed shape to honor their dark gods, growing horns, claws, and dark red skin. And even though agression and deception became rampant in this new culture, it lasted for centuries. Where other cultures had collapsed under the burden of the demonic energies, humans adapted and grew stronger.
This all changed when the Inspired appeared. As they sweeped across Sarlona, the old warring city-states collapsed in a fever of paranoia, severe aggression, and confusion. No place was as susceptible as Ohr Kaluun. For years, the rulers of the islands had protected themselves with a series of arcane mazes, laced with powerful magic to keep invaders from ever finding their strongholds. These mazes, however, could not keep the quori from invading their dreams. The few who fled the destruction of their land came to Khorvaire.
Today, the largest concentrations of tiefling populations are in the Demon Wastes and Droaam. The Carrion Tribe in the Wastes honors the tieflings as touched by their demon masters, and this culture has encouraged the worse elements of tiefling culture. In Droaam, the tieflings have gathered around Bal Molesh in the Venemous Demesne, and lead a relatively civilized lifestyle.