A surprising number of stories can make use of characters being possessed by spirits, souls, or otherworldly entities. Even seemingly mundane tales or games can be spiced up by imagining what could be done by sprinkling with the mechanism of ethereal beings, ghostly presences, and their ability to influence or control mortal beings.

Interestingly, an analysis of classical literature, mythology, and oral traditions has revealed that spiritual influence is much more common than you might think. Almost 90% of all folk stories actually contain one or more elements of people or other material creatures being actively controlled by the presence of unseen spirits.

Possession, as they say, is nine-tenths of the lore.

Transcript

Anakin: {possessing Luke, attacking Vader} You've destroyed everything!
Luke: Mother! This isn't me! Anakin's taken over!
[SFX]: Whooom!
GM: You can't speak, but Anakin can hear your thoughts.
Luke: Father, listen to me! She's always loved you, even now.
[SFX]: Whooom!
Anakin: You think you can save Padmé. You're wrong. She may have been good once, but I corrupted her.
[SFX]: Whooom!
Darth Vader: He's right.
Anakin: She turned so evil that she betrayed even me!
Darth Vader: No... you're wrong.
Anakin: You don't know right from wrong!
[SFX]: Whooom!
[SFX]: Whooom!
[SFX]: kzzrzzkk!
[SFX]: Whooom!
Palpatine: Men of broader intellect know that there is no sharp distinction betwixt the real and the unreal.
C-3PO: I'm glad someone cleared that up.