A few years ago, some people figured out how vampires work in World of Darkness and wrote an unofficial book about it. This book contained nuggets of vampire-related data that were never seen before. With the upcoming release of 2nd Edition, this book was made official and released in the Vampire the Requiem 2nd Edition book. It basically contains a whole bunch of new bloodline templates, new creatures, new blood sorcery and everything else you can think of.

If you want to create a custom bloodline that has never been seen before in Vampire, this is the book you want to check out.