- Drama: Revenant / The Devil / Demon (working & literal title)
- Revised romanization: Akkwi
- Hangul: 악귀
- Director: Lee Jung-Lim
- Writer: Kim Eun-Hee
- Network: SBS
- Episodes: 12
- Release Date: June 23, 2023 —
- Runtime: Friday & Saturday 22:00-23:10
- Language: Korean
- Country: South Korea
When the door to another world opens, demons exists there. Gu San-Yeong (Kim Tae-Ri), is possessed by one of those demon. Yeom Hae-Sang (Oh Jung-Se) can see the demon which has possessed Gu San-Yeong. They try to figure out the truth behind the mysterious deaths related to the five sacred objects.
Gu San-Yeong is busy working part-time during the day and studying to become a low ranking public officer at night. One day, she receives some articles left behind by her late father. Since then, mysterious deaths take place around her. She also finds herself slowly changing.
Yeom Hae-Sang comes from a rich background. He teaches Korean folklore at a university. Since he was a child, he has had the special ability to see demons in this world. He even saw his mother killed by a demon in front of him when he was young. Yeom Hae-Sang meets Gu San-Yeong and he faces the demon which killed his mother..
Lee Hong-Sae (Hong Kyung) is a lieutenant in the violent crimes investigation team. He only cares about advancing his career in the police department. Due to Gu San-Yeong and Yeom Hae-Sang, he gets involved in mysterious cases.