What would happen in this situation: if I, as first player, play Wharf Rats out of shadows and give control of it to my opponent, a Bara player. Following this, the Bara player plays Sister of Truth out of shadows. Per Sister of Truth's character ability, to choose one card with the shadow crest to return to shadows, the Bara player bounces Wharf Rats back to shadows.

Here's my question: does Wharf Rats return to shadows under my control, since I own the card? Or does it go into the Baratheon player's shadows area, given that it was under their control at the time? I'm guessing it is the former, considering the card is "House Greyjoy Only," but I'm still not entirely sure.

Incuus said:

It goes back to your shadows area, not because of the House restriction, but because of this text in the FAQ: "When a card leaves play for any reason, it always returns to its owner's discard pile, dead pile, hand, deck, or shadows area (depending on the specific circumstances)."

Got it, thanks for the info.

"House Greyjoy only" is a deck-building restriction and only important when building your deck before the game. It means absolutely nothing once the game itself begins.