When I read the entry in the MM, I must have missed that part at the end of the first paragraph of Misty Escape. Thanks for pointing that out.Killing in sunlight or running water prevents the mist transformation and destroys the vampire. Using the Sunbeam spell or a Sunblade (and bringing a Vampire to 0hp in their sunlight radius) is a great way to polish them off without having to hunt down their resting place.