Found this, assume it to be correct:
Captured characters retain their identity, therefore must conform to the restrictions of duplicates in play. Should a character by the same name be already in a player’s territory or set aside area, the holder of the duplicates determines which duplicate to discard.
So my follow up is this: if I capture a unique character and place it in my opponent's land of bondage, and they already have that character on their bench, do they get do pick which one is discarded, or do I?