If you used Needle to return a sacrificed character to your hand could you then play this card to return that character back into play? Seeing as Needle is an interrupt and this is a reaction it feels like it should work. The card would already be back in your hand by the time the window opens to play this right?

You bet that would work.  The character was still Sacrificed and it would be in your hand.

You can also do this with another copy of that sacrificed character in your hand!  (Instead of using Needle to put the original back into your hand)

~ See, moribund kept broken combos like that in check!  #bringbackmoribund #cantstopwontstop

You can also do this with a duplicate of a sacrificed character without Needle!

Not sure what this means?

> You cannot save a card from being sacrificed - with a dupe or by any other means. (RRG, p. 18).

> But even if you could save a card from being sacrificed, saves stop the card from leaving play, so it would not count as ever having been sacrificed, killed, whatever. (e.g., if you save a character from being killed by military claim, you don't get to trigger "after this character is killed" reactions for the character).

So I'm not sure how duplicates are supposed to interact with this card at all?

~ See, moribund kept broken combos like that in check!  

Yeah.... No, actually. Being able to play this event when sacrificed card is sent somewhere other than the discard pile is all about replacement effects, not moribund. Moribund would not actually have figured into the interaction between this and Needle at all.

I think by duplicate, Bomb meant "another copy of the same character" in hand.  Duplicate was probably not the best word, but I'm picturing it as:

-------

You have an Arya in play, with no dupe.

Another copy of Arya in hand.

Trigger Jon to sacrifice Arya.

Play this event to put the copy of Arya from hand into play.

--------

The moribund comment was regarding a character with Needle.  Such as:

---

Arya in play, no dupe, but she has Needle attached.

NO copies of Arya in hand.

Trigger Jon to sacrifice Arya.

Trigger Needle to redirect her to hand.

Trigger this event to put her back in.

 ----

While this isn't gamebreaking, it wouldn't work with moribund since Arya wouldn't be in hand yet due to moribund.

I think. You always prove me wrong so.....  

Yes, kizerman86 is correct.  I meant another copy in your hand.

I will update my OP so it doesn't sound like a caveman wrote it.

Gotcha. I was focusing on the triggering condition, not the location of the various cards.

I missed that you guys were actually, you know, playing the cards instead of mucking about with theories the way I do.