It was Perimedes who came up with Blood Rites after he suffered from a heartrending betrayal at the hands of Martha Llewellyn.
After losing an eye, the First Vampire's personality changed drastically. He was ruthless and distrustful. He was especially allergic to the words "love" and "marriage", because he believed them to be the most widespread scam in the world.
His coven members were a lot more optimistic. Although Perimedes often warned them about the side effect of falling in love, they still did. And when they did, they naturally wanted to get married.
Annoyed by the constant, nagging pleas, Perimedes felt the need to prove his point. He thus asked a powerful priestess in his coven to draw a huge magical array for him.
The two vampires who wished to be married must step onto the magical array and say their wedding oath in front of at least two witnesses.