Black Huntress (Black Butler/Hellsing Crossover)

A pure soul. It is something demons yurn for. Even vampires find themselves searching for one. Because it means that that person's blood will be all the more sweet.
However, one type of soul is the rarest, delectable, most yurned for type out there.
An old soul. A person can only have an old soul if they've died and been reborn immediately. That's the reason they are so rare. Because you have to have lived a pure life to achieve this, and so few are able to stay pure enough.
There has now been an old soul found, and hers is the eldest any vampire or demon has yet to see.
Emily will face many hardships as her past, present, and future is unraveled.
(I do not own Hellsing Ultimate nor do I own Black Butler or Black Butler 2. I only own Emily or any other character I or GinaFeatherstone create.) (This book is co-written by GinaFeatherstone.) (Some events will be similar to the animes but not all.)