So, I'm in the process of working my way through two paranormal books in two different series by two different authors.   I'm reading the latest J R Ward, Lover Reborn and I have an audiobook in the Guild Hunter series by Nalini Singh playing in my car.   The BDB book is primarily vampires but this particular book also features the angel Lassiter quite prominently in the storyline and I recently finished one of the Fallen Angels books.  Singh's Guild Hunter books feature both angels and vampires in equal measure.  

There are other series I read featuring vampires, weres, ghosts, angels, fairies, demons, shape-shifters, etc, etc, etc and I have to say it is getting damn difficult to keep all the 'rules' straight.  Can't someone write a rule book for the paranormal?  Vampires are born, not made.  Vampires can go out in the daylight, they can't, unless, of course, they are very old vampires.  They can eat and drink food other than blood, they can't.  Angels have wings all the time, they don them on demand, they don't' have them at all.  Weres are wolves, or cats, or birds, or horses, or bears, or can be any of these.  They can change on demand, they can only change during the full moon.  Paranormals are fertile, they are infertile. 

AAarrrrrrgggghhhhhhhh...someone tell me the rules!

The wonderful thing about authors is their imagination, and boy let me tell you, some of them have very good ones.  Take Ilona Andrews' Kate Daniels series, those vampires are completely different than any other.   And there are things I like with each set of Vamps.  I especially love the BDB vamps because they can eat and drink blood.  And then you have Lara Adrian's vamps can only drink from breedmates.  Holy crap, you need a rule book with a special index....LOL 

With so many series going and most at 5+ books I'm finding that I have to gloss over the previous book in the series before starting a new one.  Just to refresh my memory about the ins and outs of a particular series.   Just started reading The Mortal Bone by Marjorie Liu and didn't flip through the one before and quite frankly nothing sounds super familiar--little things here and there do--but overall, nope.   I need to find a "Book Spoiler" site (there's one for movies) and revisit this series:lol:

Hmmm, that's one of the reasons that I never read two paranormal books at the same time. (I will read a fiction book and a non-fiction book at the same time .... but never 2 fiction books, as they mix up together in my mind if I try).

I also find that I remember a series better if I read 2 or 3 at a time, instead of 1 by 1 as they are published. For example, with Sookie, I read books 1-8 all at once, and now I have been holding on to the follow-ons until I can read them in a bunch together too.

I only read my very, very, favorite series books one by one as they come out.

I like when the world has new and different rules, though ... I get tired of the same old, same old.

I read the Twilight series and then realized I liked vampire books. If you've read it, or don't live under a rock, sparkly vampires are pretty much Meyer's own thing. The thing that struck me was the common threads in all the other books. I did feel like there was a rule book at first. Now I totally understand your point. The Greyfriar (one of my favorites) by somebody Griffith (sorry no memory for this stuff) had mean vampires who were on the top of the food chain. Really interesting to completely throw in a new world.

I think thats why most sucessful authors are bringing out companion books for theirs series.  Like the Sookie Stackhouse companion that had a breakdown of every books shes written gave you a character list an discription and some extra short stories and other extra's about the books.  I find that I don't need them as I can usually remember what happened in most of the series that I read, however I find my mom needs them.  I happen to be her personal book wiki.  Before she starts a new book in a series or a book in a series she can't remember reading she calls me up and asks first if she read the last book.  Generally I say yes and then have to give her a rundown of the seires before she is like oh yeah I loved that book. 

It gets old trying to remember every detail of the series that you read.  However if every book that had vampires in them had the same description or characteristics for their vamps then we wouldn't want to read them.  If its just the same old same old and there was never anything different about the supernatural species there would be no point in it so I love when authors get creative and switch it up a little.