Itachi Uchiha and his unique ability to use the Sharingan. The Sharingan allows him to see the slightest movement and copy techniques, it also allows him to see through genjutsus, and use genjutsus by making eye contact. But Itachi can also use an evolved version of the Sharingan, called the Mangekyou Sharingan. This allows Itachi to use "Tsukuyomi," this allows Itachi to invade one's mind by making eye contact and trap him/her in a world of his design that seems to last 72 hours, but in reality only last 3 seconds. He can also use "Amaterasu," whatever he looks at will be engulfed in a black flame which burns anything, even fire. And finally he can use "Susanoo" which takes the form of a giant humanoid that wields the Totsuka sword and Yata mirror. The sword seals whomever it strikes in a dream-like world, and the shield can deflect anything that hits it.