Itachi Uchiha

Extended Family and Key Ancestors
Shisui Uchiha (Distant cousin / "Older brother" of the soul):
Although technically his cousin in the clan's line of succession, Shisui was Itachi's best friend and a brother figure to him. They shared the same pacifist ideals and the desire to protect Konoha from the shadows without starting a war. Shisui's death (who committed suicide by giving his eye to Itachi to prevent it from falling into Danzō's hands) was the greatest trauma of Itachi's youth and the catalyst for Itachi awakening the Mangekyō Sharingan. From Shisui, Itachi inherited the true meaning of "shinobi sacrifice."
Madara and Izuna Uchiha (Ancestors):
Although he didn't know them directly during their lifetime, Itachi grew up under the enormous historical shadow of these two brothers, who founded the clan as it was known. Itachi used Madara's figure and legends to construct his criminal facade when he joined Akatsuki, pretending to follow in the dark footsteps of the former leader.

Sasuke Uchiha (Little Brother):
The center of Itachi's universe. From the moment Sasuke was born, Itachi became his protector, mentor, and hero. The love he felt for him surpassed any military duty or moral code. Paradoxically, to keep him safe from the coup and the village elders, Itachi was forced to break his heart: he became the "villain" in his life so that Sasuke would grow up with a clear purpose (to become strong enough to exact revenge) and thus die as the hero who restored the clan's honor. His famous line before striking him on the forehead, "Sorry, Sasuke, maybe next time," is a reflection of that repressed love.
Fugaku Uchiha (Father):
He was the leader of the Uchiha Clan and the head of the Konoha Military Police Force. Fugaku was a stern, proud man and the mastermind behind the coup against the village. Initially, his relationship with Itachi was highly demanding, as he saw in him the clan's future. However, Itachi clashed ideologically with him because Fugaku prioritized the family's pride over the village's peace. Despite the tension, in his final moments, Fugaku demonstrated unconditional love for Itachi, telling him he was proud of him and asking him to take care of Sasuke before allowing himself to be executed.
​Mikoto Uchiha (Mother):
A profoundly loving, kind, and perceptive woman. Unlike Fugaku, Mikoto understood the immense emotional burden and sadness Itachi silently carried due to his double life as a spy. She always served as a haven of peace within the home for both brothers. Like her husband, she accepted his tragic end at Itachi's hands with complete understanding, assuring him in her final moments that, regardless of the path he chose, she would always love him.

Bukijutsu: Shurikenjutsu (Weapon Mastery)
Itachi's handling of throwing weapons was legendary, surpassing even the best instructors in Konoha since he was a child.
He was able to throw kunai and shuriken with perfect curved trajectories, making them collide with each other in the air to change their course and hit absolute blind spots (even behind heavy obstacles).
5. Physical Attributes and Intelligence
Genius-Level Intelligence: His greatest ability. Itachi was an impeccable analytical strategist. He could decipher the workings, weaknesses, and range of any enemy technique in a matter of seconds (as demonstrated by discovering the weak point of Nagato's Chibaku Tensei).
Incredible Speed: Although he did not rely on Taijutsu, his speed of movement and execution of hand seals was so high that even experienced users of the ordinary Sharingan could not keep up with his hands.
Note/Weakness: The only real limit to Itachi's arsenal was his low physical stamina. He suffered from a terminal lung disease, and the constant use of the Mangekyō Sharingan caused him immense pain and progressive blindness, preventing him from sustaining excessively long battles in his adult life.

Genjutsu (Illusion Techniques)
Outside of Tsukuyomi, Itachi was a genius of ordinary illusions, able to activate them without the enemy noticing.
Visual and Finger Contact Illusions: He didn't need to be looked in the eyes; he could put someone in a Genjutsu just by pointing his finger at them.
Crow Genjutsu: He used to project his body or vanish into a flock of illusory crows to confuse, interrogate, or flank his rivals.
Izanami: The ultimate jutsu of the Uchiha clan that alters fate in exchange for eternal blindness in one eye. It creates an infinite time loop within the victim's mind, from which they can only escape by accepting their true destiny and abandoning their arrogance.
3. Ninjutsu (Elemental and Sealing Techniques)
Itachi mastered the chakra natures of Fire, Wind, Water, Yin, and Yang.
Fire Style (Katon): Like all Uchiha, he perfectly mastered the Great Fireball Technique. He also used advanced variations such as the Phoenix Flame Technique, in which he would often hide shurikens inside the fireballs to make the attack unpredictable.
Water Style (Suiton): Capable of performing high-level water jutsus without the need for a giant external source, such as the Water Dragon Missile Jutsu or the creation of water clones that could explode at will (Explosive Shadow Clone).
Kage Bunshin no Jutsu (Shadow Clones): He mastered this technique to such a high level that he was able to perform the hand seals at a speed imperceptible to the human eye, making it seem as if the clones appeared out of nowhere.

The Kekkei Genkai: Dōjutsu (Eye Techniques)
The core of Itachi's power lay in his eyes, being an undisputed master in their use.
Sharingan (Three Toads): It allowed him to predict the enemy's movements, copy jutsus (of Taijutsu, Ninjutsu and Genjutsu type) and see the flow of chakra with perfect clarity.
Mangekyō Sharingan: Awakened after witnessing the death of his best friend, Shisui Uchiha. With this eye, Itachi had access to three of the most devastating techniques in the series:
Amaterasu (Right Eye): The highest level of fire jutsu. It creates black flames at the focal point of its gaze that do not extinguish until they completely consume their target, being capable of burning even ordinary fire.
Tsukuyomi (Left Eye): One of the most powerful Genjutsu techniques in existence. It traps the enemy's mind in an illusory world where Itachi completely controls space, time, and mass. It can torture the opponent for what seems like days in the illusion, while in the real world only a second passes, destroying the victim's mental collapse.
Susanoo: Upon awakening both eyes, he was able to summon this giant red/orange chakra armor. Itachi's Susanoo was special because it wielded two unique spiritual mystical weapons:
The Blade of Totsuka: A mystical fire sword that seals anyone it cuts into an eternal Genjutsu inside the gourd that serves as its hilt.
The Mirror of Yata: A sacred shield that can change its elemental properties to counteract and nullify any attack (physical or spiritual), making it virtually invulnerable.

Traits of their Daily Behavior
Even within Akatsuki, its true nature seeped through in small details:
Respectful and Courteous: Unlike other criminals, Itachi rarely started a fight if he could avoid it. When speaking with enemies, he was usually polite, formally apologizing before attacking or advising them to retreat so as not to harm them.
Analytical and Observant: His intelligence was brilliant. He didn't make impulsive decisions; he calculated every move, anticipated the intentions of others, and maintained total control of the situation.
Melancholic and solitary: He lived immersed in deep sadness and guilt for the decisions of his past. His gaze was often nostalgic and lost, silently bearing a terminal illness and the weight of having destroyed his own clan.

The Facade: The Cold-Blooded Criminal
To the rest of the ninja world (and to his brother Sasuke for a long time), Itachi appeared as a monster:
Cold and Distant: He displayed absolute indifference towards human life and an imperturbable calm, even in the most intense battles. He never lost his temper or showed panic.
Cruel and Calculating: He was capable of using extremely painful illusions (Genjutsu) (such as Tsukuyomi) to mentally torture his opponents or his own brother, arguing that he did so to measure his own capabilities.
Arrogant (Apparently): He spoke with overwhelming superiority, reminding others of the power difference between them and his Sharingan.
2. The True Essence: Sacrifice and Pacifism
Behind that killer's mask, Itachi's reality was completely different. His true psychological traits were:
Pacifist due to Trauma: Because he witnessed the horrors of the Third Shinobi World War when he was only 4 years old, Itachi developed an absolute aversion to violence and war. His entire life he sought peace and stability.
Premature Maturity: From a very young age, his way of thinking was not that of a child. The village leaders said that by age 7, Itachi already thought and analyzed life with the logic of a Hokage. He was a philosopher trapped in the body of a soldier.
Unconditional Love (Brother Complex): Sasuke was the center of his universe. His love for his younger brother surpassed any moral code, military duty, or self-respect. Everything he did, even becoming the "villain," was to protect Sasuke's life and force him to become strong.
Loyalty and Extreme Sacrifice: He possessed an iron will and unwavering loyalty to the Village Hidden in the Leaves (Konoha). He chose to bear the hatred of the entire world, be branded a traitor, and live in guilt in order to prevent a civil war that would have destroyed the village.

Hair: Jet black, long and straight. She wears it tied back in a low ponytail with a red ribbon, with two long strands framing her face at chin level.
Eyes: Naturally dark (dark gray/black). However, most of the time we see him in the series he has his Sharingan (three tomoe) or his Mangekyō Sharingan activated (with a design of three black blades on a red background).
Facial Features: His most distinctive feature is the deep expression lines that run diagonally from the inner corner of his eyes to his cheeks, giving him a mature, serious, and sometimes tired appearance.
Physical appearance: She is of slender, slender, yet athletic build. She is approximately 1.78 meters tall and has a rather pale complexion. The Akatsuki Cloak: The classic long, black, high-collared cloak, decorated with red clouds outlined in white. She often wore her left arm out of the sleeve, resting it at chest level.
Underwear: Underneath the cape, he wears a dark navy blue V-neck t-shirt and matching trousers.
Protective Gear: He wears traditional shinobi chainmail armor under his shirt. He also wears gray/blue arm and leg warmers.
Footwear: The typical blue shinobi sandals with white socks. Headband (Hitai-ate): His Konoha headband, which he wears on his forehead, has a torn horizontal line that crosses the leaf symbol, marking his status as a rogue ninja.
Akatsuki Ring: He wears the organization's ring on his right ring finger. It is red and bears the kanji 朱 (Shu, meaning "Scarlet" or "Vermilion").
Painted Nails: Like all members of Akatsuki, she has her fingernails and toenails painted, in her case a dark purple or black color.
Necklace: Wear a necklace with three intertwined metal circles or rings on a black cord.