It's a tricky balance to strike, I imagine. If you've hit the point where they beg for death, you're at the entrance to the butter zone for revenge on them. But if you go too far you could exit the other side of the butter zone and head straight to the part where they're, well, like she was. Completely shut off to the world around them. Broken. Probably not as satisfying to put them down at that point as it would be while they're still actively suffering enough to want death. Although, that does also sound better now that I said it. The final torture was not giving them relief when they could still hope for it? I dunno. This is probably more than I care to think about this sort of thing already.