Jutsu: Sharingan mykengo sharingan way too many more to talk about it
History:Itachi has been considered a genius since a young age, graduating at the top of his Academy class at age 7, attaining initial activation and mastery of the Sharingan by age 8, and becoming a Chunin at age 10. These accomplishments led the members of the Uchiha clan to think of Itachi as the clan's strongest member and, in turn, the clan's future. Itachi's father, Fugaku Uchiha, was the biggest proponent of this idea and focused much of his effort into bettering Itachi's career and status within Konohagakure. Because of his focused attention on Itachi, Fugaku paid little attention to his other son, Sasuke Uchiha. As a result of this neglect, Sasuke attempted to win his father's attention by training to be better than Itachi. Itachi would often offer to help Sasuke train to accomplish this goal, though he never lived up to his promises. To compensate for this, Itachi tried to force their father to spend time with Sasuke by refusing to carry out his other tasks unless his father complied. While Fugaku did so, much of the time he spent with Sasuke was still focused around Itachi, and Sasuke continued to desire his father's attention.
At the age of 13, Itachi became a squadron leader of the ANBU. After joining the ANBU, however, Itachi began to ignore his assignments and at the same time became a prime suspect in the death of Shisui Uchiha. While Shisui had been a good friend of Itachi and had appeared to commit suicide, the clan began to suspect the suicide was faked and that Itachi killed Shisui. As this lack of faith began to spread, Itachi began to distance himself from the clan, attacking its members when provoked and voicing his opinion that the clan itself was hopeless. As a result, the relationship between Fugaku and Itachi became estranged, and Fugaku started spending his time training Sasuke in an attempt to steer him away from following in Itachi's footsteps. Just as Sasuke began to receive the attention he so yearned for, he returned home one day to find that Itachi had killed every member of the clan. When questioned why he murdered their entire family, Itachi replied that it was "to test [his] ability", though he felt that Sasuke was not worth killing. Before leaving he encouraged Sasuke to live a life of hate and get strong enough to defeat him and avenge the clan. To help in this regard, Itachi told Sasuke of how to gain the Mangekyo Sharingan: one must simply kill his or her closest friend, just as he had done to Shisui.
At some point in time Itachi joined the organization Akatsuki and was partnered with Kisame Hoshigaki. While it stands to reason that he joined after massacring the Uchiha clan, the timeline that has been given throughout the series (coupled with his age) strongly suggests that he joined the organization prior to killing his clan. As a result, the exact time at which Itachi joined is as of yet uncertain. After joining Akatsuki, Itachi was confronted by Orochimaru who attempted to steal his body for his own use. With his Sharingan, Itachi was able to negate Orochimaru's efforts and sever his left hand, forcing him to flee the organization. He later proves instrumental in recruiting Deidara to Akatsuki, forcing him to join by defeating him in battle.