I recently played someone who was adamant that since it was the only character in play, his twice-duplicated unique character only had to lose one of the duplicates to satisfy the claim. Is this correct?
If there was another character in play, could he have actually removed two of the duplicates to save the other character?
When an effect (like 2+ value military claim) kills more than one character, those characters are chosen, then all die at the same time. That means each character can only be chosen once for any military claim, no matter what its value is. So since the unique character can only die once for any single military claim (no matter what the claim value), it only needs to be saved once.
So, on the one hand, if you only have 1 character in play, you only need to save it once, no matter how high the opponent's claim value. But on the other hand, if you have a character in play that can be saved multiple times, other characters in play cannot "hide behind" that character when the claim value is higher than 1.