toritaten

A "nen beast" created when Knuckle Bine's Potclean transforms.
It looks like a purple cat with a pair or red wings and the hiragana と ("to") on its forehead.
Its ability is to latch onto its victim and force them into the "zetsu" state, preventing them from using nen.

Called I.R.S. (Individual Ren Suppressor) in the English translation.