Modern day tieflings don't even have 'evil tendencies' - they are no more inclined towards a particular alignment than humans are, and carry no intrinsic evil. Not everyone knows or accepts this, however, and they are often treated with mistrust or shunned, and that in turn leads many tieflings towards darker paths, or towards accepting invitations from lower plane entities who are always willing to reach out to the vulnerable with 'help'.
As Piff mentioned - while a lot of teiflings do come as a result of physical unions, that's not the only way it occurs. Ritual and pact-forging are just as common as being sources of tiefling blood or ancestry, and most of the Elturel refugees we meet in the game were likely not always tieflings at all, but ended up that way as part of the planar event that was the Descent - though short of an individual telling you their story, there's no way to tell whether they were born that way, or changed by the planar incursion.
Last edited by Niara; 19/10/23 10:34 PM.
