The Youma of the 1992 Sailor Moon anime seemed to blur the line between vampire and demon.
Youma, under Jadiete's command, didn't drain energy directly from people, but rather had to use an object provided to drain energy.
By contrast, Nephrite's youma could directly drain energy, but they had to be placed inside an object and wait until the person using the object had reached their maximum energy.
Zoisite awakened the Seven Great Youma that evidently reincarnated as humans and as well as turning people into youma. However, these youma didn't seem to have any life-draining abilities. The same is true of the humans turned into youma by Kunzite.
Vampire or Demon?[]
Nephrite's youma best fit the vampire concept as they drain energy directly. The youma under the other generals are less clear as they either must use objects or don't seem to drain life energy at all.