Possession

Possession is the ability of witches, Traveler witches and passengers, and the Spirits to place one's spirit into another being's form and take control of their body and mind. This is typically done by magical means, through the use of spells. A few other supernatural species, such as the oni, banshee, and dybbuk, can naturally possess other beings, similar in action to a witch's spell.
Possession is different from Mind Compulsion and mind control, in that the being's spirit or life essence has to metaphysically enter the body of another being in order to control the body from within. Dahlia's Kenning is similar in manner to possession as she can "possess" and control a large number of people at once without the need to move her spirit from her body. Malivore and his vessel, Landon Kirby share similarities to possession, though this is more physical as Malivore's body enters and controls Landon as opposed to a spirit and a host.