The technique is activated upon direct contact with the target - either through the skin or visually. The Ketsuryugan user locks the opponent in a genjutsu and chooses its effect. One option is to turn the victim into a will-less executor with a given command. Another is to plunge it into a sleep-like state. To protect the mind, the technique creates a powerful barrier that blocks mind reading. There are also mentions that the user can place genjutsu guards in their own consciousness and view the target's memory. The technique may be more versatile than the Sharingan's genjutsu, since it only requires seeing one's target visually, without the need for mutual eye contact.