In fact, the only way to get the item is to use extremely metagamey option prior and some shenanigans to prevent the event from firing in the first place.
I'm not judging you but you wouldn't be frustrated if you didn't know about the reward. I don't know if you're experienced on playing games like this but when we saw dark urge we knew it would be an origin that would sacrifice a lot of things (maybe even companions) so we didn't choose it. You can't get everything in this game unless you spoil most of the things to yourself and that's not fun at all in my opinion. I'd recommend you try to enjoy the story and the way your origin interacts with it.
You can wait before fufilling your Dark Urge until the sidequests are done. Part of being a serial killer is choosing the right time
Thanks for the spoiler, I guess?
To answer your question, I got it on my first playthrough, but didn’t on my second one. I was confused what was going on, as that didn’t happen before and the quest was still active. LO and behold, it's a bug, glitch or something to that effect.
And your advice of "enjoy the story" does not seem to understand my problem with it. The problem isn't losing an item to an only origin but a bloody bug. See, you save all the tieflings in ACT 1 and 2 and should in theory receive a reward.
Unfortunately the game gets very confused with npc being dead in a cutscene and doesn’t fail the quest or let you finish with different npc. It’s literally glitched.
As for the other commenter, they don't seem like they played the character.