Puppies are cute, but by no means should one choose their dog solely on the looks of the pup. If you do not choose the right type of dog and provide leadership and daily exercise, your adult dog could grow up to be a holy terror.
Visionary serial killers suffer from psychotic breaks with reality, sometimes believing they are another person or are compelled to murder by entities such as the Devil or God. The two most common subgroups are demon mandated and God mandated.
By extension, a visionary can also be a person with a clear, distinctive, and specific (in some details) vision of the future, usually connected with advances in technology or social/political arrangements. For example, Ted Nelson is referred to as a visionary in connection with the Internet.