Ustus is considered the homeland of the Tieflings. Within the center of Ustus is the Great Eldritch Pool, from which many abominations have arisen. Ustus was once part of the Kingdom of Scaydor. Scaydor at the time was considered one of the most powerful nations in the Magelands due to its access to kosem stones and [[Great Eldritch Pool:Lake Ustus]]. However, kosem mining and war with the neighboring Cloeca led to Lake Ustus becoming corrupted with dark magics. Eventually, the creatures that arose from the corrupted lake led to the kingdom of Scaydor withdrawing from the area. The commoners that were left behind in the region became corrupted, becoming the modern-day Tieflings.
Ustus has no settled government, from time to time a warlord will rise and announce itself King, but within a few years be pulled down. Attempts at forming a more democratic society often fails in part due to the Tieflings’ selfish ways.