One thing I've always loved about vampire stories is that there are no hard rules. Vampires can be whatever the author wants them to be as long as they're internally consistent within the story. This makes them extremely versatile monsters that can be constantly re-invented and none of them are "wrong".
For example, sometimes all it takes to turn into a vampire is to be bitten by one. And sometimes you have to drink the vampire's blood to turn. Or, sometimes a vampire can just drain your energy without transferring any blood at all.
Of course, the rules can also get a bit ridiculous. Maybe the vampire is required to obsessively count grains of rice first. Or maybe they're required to hop around with their arms out (the chinese Jiangshi). Maybe they can turn into a wolf, a bat, or... fog.
So what's the most ridiculous rule or type of vampire you've come across?
(For the image on this post I wanted the most ridiculous picture of a Jiangshi I could find. I went with a shot from Robo Vampire which has a really fun RiffTrax. The only other Jiangshi I'm aware of is in the NES game Phantom Fighter... because I've never watched any of the Mr. Vampire movies)
one of the wierd ones is the vampire feeds on said humans, but have to feed its blood to turn them. and in SPN they have a magical cure for vampirism, if the infected hasnt fed yet. castlevania also does it this way. Also in the same show, apparently you can absorb magic powers through biting the victims, in this a "god's power spirit energy. also the wierd part of vampire evolution is in various genre, they can be made immune to sunlight, mostly through magical rituals or given magical power by a more powerful vampire. akasha giving sunlight immunity, or the short lived blade series on spike, or
Unless I'm misunderstanding you, that's not especially weird. In fact it's very, very standard, and has been since Dracula did it that way in 1897.