As the source of power for all Yōkai, Yōki is used whenever a Yōkai is using one of his/her abilities. However, as Yōki is also a Yōkai's "lifeforce", if the Yōkai overuses it or runs out of it, then he/she will die. The following list are some of the possible ways that Yōki can been used for:
- Youjutsu: The art of manipulating Yōki into barriers and working with seals.
- Yōki Conversion: By channeling their Yōki into their musculature, Yōkai have been shown to be able to generate high levels of strength.
- Yōki Detection: Some Yōkai have shown the ability to detect another Yōkai's Yōki and their emotions. This leads them to be able to pinpoint where an enemy is as well as predict when the enemy will attack.