One of the things I've wondered about is this... Even if Gatts or Skull Knight do "kill" all of God's Hand, what would happen? Would it be possible to summon them again, at the next eclipse? If so, what would happen to the sacrifices from the previous summoning?
When the demons ins Berserk die, are they really gone? Or can they be reborn, like Griffith? If they could, what implications would this have for people like Gatts and Casca who have been marked? Haha, who knows, maybe I just think about this stuff too much.
I haven't read much of the more recent manga, so I don't know if this is answered in there, so I apologize if I'm bringing up something we already know.
~Shaughn