Elements of a Vampire and related beings?

[Abrigon Gusiq]

I see three(?) basic themes in Vampire Movies:

Classic is Dracula and like.
Modern is Blade and like. Underworld maybe as well?
Twilight, is sicky sweet but..
Classic based on Bram Stokers ideas, is a super natural or like beast.
Curses by God or A Fairy or like being, doomed, curses or blessed to
walk they earth until when? Christ comes back, like Judas or end of
the world or ... Some beings have some elements of a "vampire" or
like.. I know some of mine, are beings who want more power, or unable
to connect with the power grid and have to suck the blood of those
still connected to the grid to get more projected power until the
nanites they have taken in become inactive due to the grid finding out
the nanites are no longer in the being they are supposed to be in and
other issues.
Some elder god still around but doomed or damned, curses to suck the
blood of the living to sustain its existence.. Blood or spirit.
Count Dracula and Professor Van Helsing.
Vlad Tepis and Dracula (son of the Dragon?).
Van Helsing and Dracula and the Brides of Dracula?
Underworld and like?
Twilight?
High Lander and like - Aliens or .. Immortal but not a vampire,
but ...Wraith from Star Gate, they suck the essense/spirit and
memories of the one drained.. Genetic memory or .. like the Magog? or
Borg live on as cybernetic but mindless drones or ..more like
zombies?

http://en.wikipedia.org/wiki/Vampire

why do the Blade or Twilight Vampires go poof/ash? Plot device to make
it easier to clean up, less mess, unless its the human that gets
accidently killed and you have a body to deal with. Or its the "power"
they have inside that when no longer able to be held together, it
burned up, but where is the heat from a "burn up". or its more like
since they are dead, they are just barely from being rotted or like?