Demuncher

is an Earth-attributed S-ranked Yo-kai of the Brave tribe. He is a pupil of Master Nyada. In the Japanese Yo-kai Daijiten (Yo-kai Dictionary), it states, 'This is a scary yo-kai because he loves to eat oni's. He has a big mouth that allows him to swallow them up whole, but he sometimes gets a stomach ache from it.'

Relationships
Master Nyada.- In Yo-Kai Watch 2, after the third sidequest requested by Master Nyada, which involves a battle with Oni-kui, it is revealed that he is a pupil of Master Nyada. Oni-kui clearly holds the cat Yo-kai in high regard.

Abilities and Powers
Oni-kui is able to devour any Oni unfortunate to be in the way of his jaws. The Boss version of Oni-kui seen in Yo-kai Watch 2: Shin'uchi is big enough to eat Oni the size of Gargaros with contemptuous ease.

YW 2
Onikui-Attacker

How to get
Do the quest: Nyada's Test Episode 2 in order to be able to battle him once everyday at the top of Kiuchi Mountain (Past). You have to befriend him in order to complete the quest.

YW 2
Oni-kui' s soul- When equipped, the equipped yo-kai will land critical strikes on the opponent very easily.