Uchiha Madara

Madara Uchiha (うちはマダラ) was the leader of the Uchiha clan prior to and after the formation of Konohagakure. He also helped to found Konohagakure.
Before the era of ninja villages, Madara was the most gifted member of the Uchiha clan. Even by his clan's standards, Madara's chakra was unusually strong. He grew up constantly competing and training with his younger brother,Izuna Uchiha. In their efforts to surpass the other, each gained their own Mangekyō Sharingan. With the power of the Mangekyō the two brothers took control of the clan, with Madara as its leader.
Because of the never-ending series of battles of the time, Madara eventually began to suffer from overuse of the Mangekyō Sharingan, leaving him blind. In order to regain his sight he took Izuna's eyes for himself, granting him an "eternal" Mangekyō Sharingan with which he led the Uchiha clan to prosperity. While Itachi Uchiha would later go on to state that Madara took Izuna's eyes without his consent, it is unknown if this is actually true.
Over the years, the Uchiha had constantly fought with the equally powerful Senju clan and as such, Madara had an undying rivalry with Hashirama Senju, the leader of the Senju clan. To bring an end to the constant fighting, Hashirama approached the Uchiha with an offer of peace. Although Madara never wanted peace with the Senju, the rest of the Uchiha wished to end the fighting, and Madara had no choice but to accept. The Senju, the Uchiha, and all the clans they had conquered came together to form the village of Konohagakure. 
Decades later, a masked-individual known as Tobi began operating under Madara's name. Tobi is intimately familiar with Madara's history, sharing his animosity towards Konoha and the Senju and even going so far as to claim that Izuna willingly gave up his eyes. It is, therefore, difficult to say which actions were those of Tobi and which were those of the real Madara. At the very least, Madara is aware of Tobi's existence. This masked man is known to have manipulated the Fourth Mizukage, been the cause behind the Nine-Tails' attack on Konoha, participated in the Uchiha clan massacre, and taken a hand in creating and leading Akatsuki.

Personality


 As an Uchiha, Madara possesses an innate hatred against the Senju clan, in what is known as the Curse of Hatred, which dates back to the early days of the ninja world. This curse led him to oppose the truce fearing that his clan would be oppressed by them, and when Hashirama was selected to be Hokage instead of Madara, he defected from Konoha and attempted to attack the village. His animosity to Hashirama was particularly strong, going as far as to forbid Ōnoki from mentioning that name in front of him ever again.

Abilities


Madara is considered by many notable individuals to be one of the most gifted shinobi in history and the most powerful that has ever been produced within the Uchiha clan. He has been noted to have been born with particularly powerful chakra, which even the Nine-Tails claimed to be far more sinister than that of its own. 
The fact that he fought and survived numerous battles with Hashirama Senju, who was recognised as the strongest ninja in the world in his time, prior to their truce indicates that Madara was also one of the strongest ninja of his time. Madara is one of the only shinobi in history capable of summoning the Nine-Tailed Demon Fox, the other being Tobi. However, it's sealing inside Mito Uzumaki and later Naruto Uzumaki have left him unable to do so.

Uchiha Sasuke

Sasuke Uchiha (うちはサスケ, Uchiha Sasuke) is a main character in the Naruto series. He was originally introduced as a protagonist, a member of Konohagakure's Team 7. As the series progressed, he became an antagonist, culminating in his association with Akatsuki, becoming one of the most dynamic characters in the series. Sasuke is currently amissing-nin, an international criminal, and most likely the last surviving member of the Uchiha clan.
 As a child, Sasuke grew up in the shadow of his older brother, Itachi Uchiha who was an acknowledged prodigy viewed by the Uchiha clan as a genius, and whose work would further strengthen the bonds between the village and the clan. 

Personality


When he was a child, Sasuke was a very kind boy, loving towards his parents and brother, and respectful to his fellow clansmen as well as his teachers. He was even very proud of being Itachi's brother and Fugaku's son, famous for being devoted protectors of Konoha, and he always desired to emulate them. 
When first introduced to Team Kakashi, Sasuke displayed great indifference to his team-mates. Feeling superior to all of them, including his teacher, Sasuke was unwilling to cooperate with Naruto Uzumaki or Sakura Haruno, as he felt they would provide him no aid in killing Itachi. However overtime, as he spent more time with his team, he begins to see them as somewhat of a family and Sasuke starts to lose some of his anger, caring more about his team than his revenge. Sasuke even admitted to Naruto that he almost thought that he should forget revenge and instead focused on Team 7. To help push him back into his desire for power, Orochimaru branded Sasuke with the Cursed Seal of Heaven during the Chūnin Exams to give him a taste of power. Although Kakashi Hatake sealed the Cursed Seal, as well as teaching him the Chidori in the hopes of deviating him from the path of revenge, Sasuke began to draw more power from the seal in the hopes of getting stronger.

Abilities

Sasuke is established as a genius, even by the battle-excelling Uchiha clan's standards at the series' start, excelling at all that he does and finding little difficulty in more challenging tasks. 
By Part II, he develops much of his potential and becomes a very powerful ninja, strong enough to fight on par with several highly skilled shinobi. Admittedly, in his battle against Orochimaru, Sasuke downplays his victory, and attributes it to Orochimaru's sickly state.According to Tobi, Itachi had already determined the outcome of their fight, and was sick as he was using medicine to prolong his life. This didn't prevent Itachi from praising Sasuke however, saying if he didn't use Susanoo he would have been killed by Kirin. However, Sasuke managed to survive a fight with Deidara, a powerful and dangerous S-rank ninja well known for his abilities, without any form of handicaps. After receiving his Mangekyō Sharingan, Sasuke proved capable of holding his own against at least two Kage and their bodyguards, before being weakened to the point of exhaustion due to his battle with them.