It's all about the blood.
I was going to write a fourth book in the Witches of Galdorheim series. It was supposed to be Rune's book. You probably don't know who Rune is either, so I'll first introduce him a bit, then talk about the characters you'll not have the opportunity to meet in the Galdorheim series.
When first turned, however, he didn't have proper control yet. He attacked Rune's mother intent on taking her blood while they engaged in a bit of hanky-panky. Ardyth, a powerful witch, nipped that in the bud (so to speak) and returned home carrying Drakos' child, Rune.
Helsing and Liebchen: Helsing is a distant relative of the famous Van Helsing who took on Dracula in Bram Stoker's seminal work. He isn't the brightest bulb on the tree, but desperately wants to make a name for himself as a vampire hunter to follow in his ancestor's footsteps.
The hound can also close their ear canals at will (to protect them against dirt and moisture) and are able to bend their head 180 degrees backwards over their shoulders. Their fore-shoulder joints are extremely flexible and empower both front legs to be stretched straight out to both sides, for greater ease in swimming and maneuvering in the narrow crevices in Norwegian seaside cliffs where their avian prey lives.
The dog, for all its traits and talents, has a flaw of its digestive tract which requires an almost 100% protein diet. Thus sensitized to detect protein sources, the Lundehund is ideal for seeking out creatures which also require high protein foods, such as vampires. Blood calories are almost all protein. It does contain a high salt and iron content, which might be detrimental to humans, but vampire and Lundehund physiology can counteract the potential poisons.
Biel the Mahr: The Mahr are a race of giant vampire moths that dwell in the Carpathian Mountains. When a person was bitten by one of the Mahr, the creature would host the body of that person. A Mahr can be killed, and thus returning the soul to the original owner, by driving a wooden stake through its heart, or by finding its lair and exposing it to daylight. In Poland, they are called Mora and in Bulgaria Morava. The Mahr needs substantial quantities of blood to survive cocooning for several years.
Early on in the book-which-will-not-be, Rune and Drakos must fight off a Mahr named Biel. Not usually enemies, Biel is upset because Drakos has banned blood-taking in the area enforcing the rules via his control of a variety of folkloric creatures which were to be determined if the book had been written.
The Witches of Galdorheim series is available in ebook, print, and audio formats. I have given out the links a thousand times, so no reason to bother repeating myself.