Cuffs. Itachi didn't know much about them either, and he had no further questions to add on top of Sasuke's own. Not yet. If his brother couldn't get anything more out of him then he would push the genjutsu further, but not yet. The other ninja had a good enough handle on things.

Their abilities were already weakened here - that much was apparent, especially in how much they were tired out after enough use of them. That there was a way of sealing them off further shouldn't have been a surprise, but it was still important to have it confirmed. Anything they could learn about it and how to keep it from being used against them would be helpful. Of course, given the competence this man had shown so far, who could say if he really had much else worth adding. Those who knew what they needed were most likely not even placed on the field.