Origins of tieflings
Tieflings are usually the result of a demon or devil forcing themselves on a half-elf, human, gnome, halfling, nøkkans or gargil. You may choose some cosmetic features from one of these races. Vestigal wings or elven ears, from gargil or elven parentage for example.
Having an act of violence in your family history, has its own set of generational trauma that follows it. It is also visible on your body, and evident to all you pass… Many tieflings are orphans, or leave home in efforts to try to escape their past.
After the War of the Swarms demons and devils started pouring into the world on the peninsula of Arkrak. The number of tieflings in the world has steadily increased since then, and many tieflings have their origin in the Nill area. Something they might be trying to escape.