YMMV / Caliban

• Complete Monster: The body-snatching alien, known as Karien after its human host, is a sadistic being of electrical impulses that possesses sapients. It is made clear the alien is a thinking, sapient being who simply doesn't care at all about the lives of others. When the Caliban stumbles on a derelict alien spacecraft, it is revealed that the alien Karien massacred the prior crew. Upon possessing its host, Karien brutally tortures and kills crew members, partially to figure the limits of human physiology, and partly for fun. When it understands human limits enough, Karien proceeds to enhance the body with alien technology before slaughtering the remaining crew save two. Karien intends to force them to take it back to Earth so it may proceed to enslave it and rule over it by using humans as tools or bodies to possess.