[Coda]

Because the Barber is an extremely powerful demon with the power to cut absolutely anything. Anything it separates can never be reunited whole; there will always be pieces missing. And it can make this cut in any way it wants to, even if the thing being cut is an abstract concept -- simply slicing an object in half effortlessly is the LEAST horrifying use of its power. It can cut the relationship between two people, for example, or it can even cut the wounds off of someone, leaving them uninjured (but with a permanent loss somewhere), et cetera -- I hesitate to explain too much lest I make very significant spoilers.