Itachi
Uchiha
Ninjutsu (忍術; Literally meaning "Ninja Techniques"), is a term referring to almost any technique which allows the user to do something that they otherwise would be incapable of doing, including the usage of weapons. Unlike genjutsu, which makes the opponent see illusions, the effects of ninjutsu are real. They vary greatly in purpose, with the simpler ninjutsu serving such tasks as transforming the user or allowing them to evade attacks. These techniques are often second-nature for experienced shinobi, who can use them at will. More complex ninjutsu manipulate one's surroundings or utilise the elements, respectively serving such tasks as healing others or manipulating nature transformations.
Ninjutsu, most of the time, relies on chakra and hand seals to be effective. The hands are put in sequential positions that moulds and manipulates chakra in the necessary manner to perform a technique. This is not always needed, however, and some techniques become second nature to experienced ninja, after which they can perform them at will.
Additionally, there is the kind of technique that can be classified as a basic or advanced elemental technique, the basic type are techniques with specific elements (wind, water, fire, earth, or lightning), the advanced type combine two or three of the basics elements and creates a new one.
Ninjutsu
A technique that produces a clone by projecting one's own chakra towards dozens of "crows". Because it uses crows as a medium, it requires less chakra than the normal Shadow Clone Technique, while still being able to perform techniques. The dozens of crows come together to form the body of a clone. When the chakra projected by the user is severed, the crows disperse, though the user is still able to continue to speak through it.
This technique is used to create a shadow clone that can be detonated. The clone looks like a normal shadow clone, which allows the user to get it close to the target without them expecting anything besides a normal attack, or the target might even close in willingly to try to attack the clone. Using multiple tricks and diversionary tactics to disguise the nature of the clone can make this technique more likely to be effective.
Amaterasu is the highest level Fire Release technique,[2] and according to Zetsu, the strongest ninjutsu of Itachi's eyes. It is said to represent the "Material World and Light" (物質界と光, Busshitsukai to Hikari), the antipode to Tsukuyomi, a genjutsu of similar power and a fellow Mangekyō Sharingan dōjutsu. The jet-black flames of the Amaterasu, said to be the fires from hell that are as hot as the sun, ignite at the focus of the user's vision. Though the flames have been stated to be unavoidable.
A technique where chakra kneaded inside the body is converted into fire, and expelled from the mouth either as a massive orb of roaring flame or as a continuous flame-thrower. The scope of the attack is altered by controlling the volume of chakra that is mustered. The released flames will engulf their target, and leave a crater on the ground's surface. This technique apparently requires more than average chakra reserves and most genin should not be able to do this technique.
Fire Release: Phoenix Sage Fire Technique This technique creates a volley of small fireballs, which are sent flying in an unpredictable manner assaulting the enemy. Also, the flames are controlled one by one with chakra, so avoiding them all is extremely difficult. Shuriken can also be concealed within the flames, creating an unexpected secondary surprise attack. Like the flames, the shuriken can be controlled with chakra. For the most part, however, this technique is used as a distraction.
Fire Release: Phoenix Sage Flower Nail Crimson The user unleashes a volley of shuriken with one hand, and at the same time, exhales fire-infused chakra onto them in order to increase the weapons' destructive potential by making them capable of inflicting severe burns upon direct contact with either the intended victim, or any other object caught within their trajectories.
There are several other jutsus such as these.
Fore there are no limits to his greatness.