The inspiration largely came from wanting to do the further adventures of an old Buffy, the HBO series Chernobyl, and idle wonderings why Wolfram and Hart didn't do a massive re-souling of a bunch of vampires to muck around with prophecies for fun and profit. I figured there had to be in-universe reasons for nobody trying that, watched the show, and realized I had something to work with.

In a sentence, from its summary: "It's having the choice that's important." Self-determination is one of the big themes of the show, and I was happy to pick it up and play with it a while.