That was actually already covered in a previous thread from the other day. But I will repost it here:
As for the Vampire's 'Mist Form' ability, think of it as a sort of saving throw. Each time the Vampire takes a Hit, he rolls a die. On the roll of 5 or 6, he ignores that Hit.
There is one other thing with the Vampire's Minion Chart that I should clarify as well. 'Bats' and 'Wolves' (minions of the Vampire) only take affect once. When they are encountered by a Hero, they take their affect (fight the Wolves or roll for the Bats to steal your Items), then they are removed from the board. The only time the counters for these particular minions are going to stay out on the game board is when they appear in a space where there is no Hero. Then when a Hero enters the space later, the Bats or Wolves will attack and then be removed.
Jason C. Hill
Flying Frog Productions