Mist forms while fighting vampyre juvinates, juvinates, and vampyre juveniles from Meiyerditch with Silver or Blisterwood weapons. Without the use of the special attack of either the Rod of Ivandis or Ivandis flail and a dose of Guthix balance to kill them, vampyres turn into mist and run away to rejuvenate their wounds. It is also found when Vanstrom Klause infiltrates the Myreque hideout during In Search of Myreque.
In Branches of Darkmeyer, Vanstrom Klause also turns into mist when near death. He must be lured over pools of holy water created by Vertida's bottle of holy water to finally kill him.