Look, like ArmouredHedgehog says the "subverted expectations" trope is annoying and overdone. Aishaddai makes it seem like I (and everyone else I have talked to on this forum) is missing some glaringly obvious clues that Zevlor is evil and the Tieflings in general are a thieves' guild in disguise. I just don't buy that. It's much more likely their contact in Baldur's Gate is the thieves' guild and they have a deal with them to be accomodated there as some kind of "nescessary evil" trope. If Zevlor and the Tieflings are all evil then everyone is. And I mean everyone. Not to mention Zevlor throws Alfira, the soul coin lady and a bunch of other named Tiefling NPC's with story arcs to be resolved in Act 2 - 3 under the bus.