Victims are turned into vampirirc bloodsuckers.

All Vampires you control gain the following power:
Vampire Plague Whenever a friendly Vampire slays a victim, instead of placing the victim on the monster's card, you may choose instead to remove the victim from the map and place a Minion token from outside the game in an empty space adjacent to the slayer.  The minion is friendly to you.
(You still gain victory points for slaying the victim, though the monster does not become blooded.)