I posted this theory way back, aong with my entire theory for Episodes 1-4, but I think I'll post it here again, for the people who are just now getting to read Episode 4:
Spoiler for Battler's Death:
As for Battler, this is a bit tricky, and like Kanon's Zombie, relies on a bit of word playing, I wonder if Beatrice is "Belief". No one believed Battler was alive after seeing the 17 corpses, so in effect, he was "killed".
Furthermore, what Kyrie said earlier, about "missing for 9 years then being legally dead", so since no one ever found Battler, he eventually became legally dead. He was killed off because so many people believed he was dead.