Doppelgängers

Doppelgänger are mythical beings of folklore. They exist as physical duplicates of other living people, imitating their physical form, and often even their memories and personalities. Some Doppelgängers may exist as corporeal apparitions, or shades, while others may possess physical characteristics that distinguish them from those that they resemble. Ancient traditions portray Doppelgängers as harbingers of bad luck.

In Marvel Comics, Doppelgängers played a large role in the 1992 crossover event, "The Infinity War". The being known as the Magus, who himself was something of a Doppelgänger of Adam Warlock, utilized a cosmic containment device that created Doppelgängers of many of Earth's heroes. These Doppelgängers were demonic representations of their hosts and found themselves battling up against the heroes they resembled.