I thought Sean's death was the saddest death in the entire game. Which is odd for me to think about. Sean never was a major character, Just like what Equivalent said, but i felt he Sean's survival was much like a hope, A relic of the raid in blackwater. An Icon that showed that not all of their luck was gone. So when he died, and so abruptly, it shook me. It was also the first death of a major character in the game (If i can recall) and shocked me by its quickness. Even from the beginning of the game i found myself sad about how much of the crew was disjointed after so many of their members where killed and left behind. I was generally surprised when you get to save Sean, and happily surprised by the whole mood that it brought. Personally i liked Hosea And Lenny Lot more but found Sean's death just sadder.