Genjutsu: Sharingan is a general name for illusory techniques performed through the Sharingan, as well as its advanced forms - Mangekyo Sharingan and Rinnegan. By establishing eye contact with the target, the user immerses them in genjutsu, which can perform a wide range of tasks: instant but temporary loss of consciousness or paralysis, forced extraction of information, transfer of one's own memories, memory erasure, dispelling another's genjutsu, and complete subjugation of the victim's actions.
The Uchiha clan gained particular notoriety for their ability to control the Nine-Tails using this technique - so much so that after the Fox's attack, Konoha immediately suspected the Uchiha. Sasuke Uchiha, through the Rinnegan, captivated all the tailed beasts at once with a single glance of illusion. The images generated by Genjutsu: Sharingan have no fixed form: for the same user, loss of consciousness may appear as being pierced by feathers, capture by a dark figure, or a personal blade strike. Apparently, the images shown are controlled by the one using the genjutsu.
The illusion can be cast in any version of the advanced Sharingan.