Yokai are listed in Raclis as Demons.
By definition, Demons are Angels who diverted from their purpose, choosing to desert their masters or fight them for domination over the respective world.
Yokai are from Japanese mythology and, in my multiversal lore, are usually originating from the Kami or their precursors.
As there are countless Yokai types, they are all listed under the umbrella term. From Onibi to Teke-Teke, Yokai differ in size, nature and appearance. What remains constant is either malevolent nature or vampiric, life-draining way of sustaining themselves.
Just like normal Demons are compensating for the celestial "nutrition" they gained as Angels from their gods before their fall, Yokai too must feed from something, might it be fire, life force, souls, screams, fear, thoughts or memories.