Wakeru no Oni

Wakeru no Oni seems like a frail creature at first, a hunched humanoid with long arms. Its attacks can be dodged quite easily by trained bushi. This oni seems to completely forego any defensive stance and with reason since when it is dismembered, the severed limb will shift so as to form a new Wakeru no Oni. Smaller and less harmful, it will however distract quite efficiently its attackers.

The more the bushi dismembers Wakeru, the more creatures it creates. The only way to kill it will then be to stamp every little offender to the ground before being overwhelmed by the sheer number of smaller oni attacking the bushi.