[Jack looks like he doesn't really want to answer this question. But he does anyway.]

No, I'd be dead. But it would...grow back. And then I'd revive. I don't know how to describe it more specifically. I've been through worse, but I wasn't exactly there to witness it personally, you know? Let's just say that it would hurt like hell and leave me with a killer headache, but otherwise be pretty much none the worse for wear.

[Relatively speaking. His head will still have been cut off and had to have grown back, after all. He knows from personal experience that growing his body back hurts like hell. He kind of wishes he didn't, some days.]