Yokai (Ninninger)

This article is about a group of monsters in Shuriken Sentai Ninninger.

An example of a Yokai, Kamaitachi.

"You, an object, with no will. Come alive, with the will of Gengetsu Kibaoni!"

―Gengetsu Kibaoni's command on awakening a Yokai.^[src]

"Joutan kaiyou kenjuri inpuu, (giikishi genji genja!)"

―Kibaoni generals' awakening command to create a Yokai.^[src]

The Yokai (妖怪, Yōkai) are supernaturally-created creatures made for use within the Kibaoni Army Corps as sowers of discord and destruction for the gathering of the "Power of Fear". Each is born when the darkness of any of the 48 corrupted Sealing Shuriken (封印の手裏剣, Fūin no Shuriken), originally used by the Last Ninja Yoshitaka Igasaki to seal Gengetsu Kibaoni, infuses an inanimate object. They are assisted by the Hitokarage.

There are some unique Yokai, summoned by special Yo Shuriken, called Giant Yokai (巨大妖怪, Kyodai Yōkai) that are naturally/already giant. Infusing two corrupted Sealing Shuriken into an inanimate object creates an Advanced Yokai (上級妖怪, Jōkyū Youkai), which are more powerful than the Yokai that had only been infused with one corrupted Sealing Shuriken. Infusing three corrupted Sealing Shuriken into an inanimate object creates a Super Advanced Yokai (スーパー上級妖怪, Sūpā Jōkyū Youkai),

Known Yokai

Known Advanced Yokai

Known Western Yokai

Known Giant Yokai

Giant Yokai Gashadokuro

Known Super Advanced Yokai

Super Advanced Yokai Shuten-douji

Notes

The fact that regular Yokai are created when inanimate objects are infected by Sealing Shuriken is a reference to tsukumogami, a classification of Yokai born from antiques who acquire sentience after aging 100 years.
The Western Yokai seem to be based on creatures in western mythology, more specifically from European mythology/fiction.
The Yokai share a similary concept with the Ganma from Kamen Rider Ghost, the Ninninger's second Super Hero Time partner, in that they use a power source shared with the hero and an inanimate object is infected with said item to make the monster.