Cursign

When most Tieflings began to tolerate non-tieflings again - a vocal minority resisted. The resistors found kinship and security in the remote mountain towns of Acradus. The region is dotted with small town, villages, and cities and castles. Wealthy land owners lend aid to each other and swear an allegiance to a loose alliance named the Cursign.
Non-Tiefling are very wise to avoid the Cursign region, where it is often a crime to be anything but Tiefling.
Life in the Cursign is a throwback compared to the rest of the planet. Ore, timber and crops are the major products of the region.
The wealthiest and most influential land owner is Vorgis Mulls - a man known for his xenophopic nature and hatred of anything not of infernal blood.

The Keep and surrounding mountain-town of Vorgis Mulls.