Come on! Let’s kill the bitch!
I don’t understand what a vampire needs with a gun. That’s an Alan Ball for you. xD
The gun is probably to take out Marnie/Antonia. It would allow them to be far enough away from her to kill her without being brought under some kind of spell. She seems to be able to do a better job of the necromancy when vamps are closer to her. I know that across the room isn’t really a big difference, but I’m sure that in Alan Ball’s brain, there is some kind of massive difference.