Wraiths (Mortal Kombat)

This supernatural species of entities called Wraiths are demonic spirits from the Netherrealm and they are one of the known hostile races in the Mortal Kombat fighting videogame series.

The most well-known wraiths are Noob Saibot and Scorpion. Noob had killed Scorpion as the elder Sub-Zero, and Scorpion later returned and killed him out of revenge. Sub-Zero then came back as a Wraith.

Smoke may be considered as a type of Wraith as well. In his Mortal Kombat (2011) ending, it was stated he was sacrificed to a demon, and returned to the mortal realm as an Enenra, a creature of smoke and vapor.

Freddy Krueger the legendary serial killer that haunts the dreams of the living, can also be considered a wraith, because he was once human and was brought back as an evil spirit by demons.