Death they say never liked to see Life sad he would go out of his way to make her happy. It was why even when he had to take someone home he made a way to bring a little joy. It is why a special song is written for every soul that passes. The songs can be written by someone close or a songwriter if no one is inclined to have the gift. But there is always a song it is though to soothe the soul on the journey home.
The most famous song ever written was composed by death himself in his first life. It was also the song that created a race. The race he later called vampires. Life like all concepts had a high priest and priestess. Her high priest was named Kyriakos. She was fond of him but as fate would have it he died. This saddened Mireya who decided to mourn by herself. Nikola only wanting to see her happy decided that he would bring him back.
The others had created races and he thought maybe he could also giving new life to the priest. He used the song because he knew the power it held over the soul and he created the most beautiful death son ever written and it worked the song called him back but not as he was as he thought. He thought his race would just be a witch with perhaps less magic but as a new being. A being of death that he called a vampire needing blood to survive.
The problem being that while he had returned him he was dead thus could no longer serve life. But he was the first of his kind and those that he bite became like him. And when they die they return to him. His kind grew and it became clear that when they sang it marked the death of someone starting with the concept lines with the king singing marking the death of those of Life's line or her opposite. As time moved on and more were created more family lines were marked by a vampire song.
And Life was happy to see her priest even if he could no longer have the role. He keeps it safe for centuries till modern times waiting to find someone worthy of taking it. Someone who will guard life as he would have.