Sasuke Uchiha (うちは サスケ, Uchiha Sasuke) is one of the last surviving members and the current head of Uchiha clan. Being a close friend, advisor, and former rival to Hokage Naruto Uzumaki he's often affectionally called the "Support Kage" by citizens of Konohagakure.
At a young age, Sasuke witnessed his family's murder at the hands of his older brother Itachi. Upon being asked why he did it by the young Sasuke, the elder Uchiha brother lied and said that it was to test the limits of his strength while in truth he was ordered to stop a coup that his family was preparing to execute, before knocking out Sasuke and fleeing the village. Enraged and without a family, Sasuke's personality took on an increasingly dark and brooding tone as he ruthlessly trained to become strong enough to kill his older brother. After achieving the rank of genin, Sasuke was assigned to Kakashi Hatake's Team 7, along with his rival Naruto and Sakura Haruno.
Sasuke would eventually leave Konohagakure after a heated battle with Naruto to join with the rogue shinobi Orochimaru, hoping that the sage's experiments would give him the strength needed to kill Itachi. Orochimaru had different plans, however, and attempted to kill Sasuke in hopes of possessing the Uchiha's body. Sasuke managed to stop and kill him before moving on and creating a team of Orochimaru's former experiments who would aid him in his quest for vengeance. Sasuke ultimately succeeded in killing Itachi but passed out briefly after the battle.
Upon awakening, Sasuke found himself being healed by Obito Uchiha, then using the moniker of Madara, an ancient legendary member of the Uchiha. He revealed the true reason behind Itachi's betrayal of the Uchiha and shifted his thirst for vengeance against Konohagakure. During the Fourth Great Shinobi War, Sasuke encountered a revived Itachi and joined forces with him in order to stop Kabuto Yakushi, who revived many prominent shinobi to aid Obito. During the battle, Sasuke began to question his own motivations and after talking to the revived Hokage, Sasuke decided to join the war against Obito and become the new Hokage in order to change the policies that lead to the Uchiha wanting to stage their coup.
After the war, Sasuke fought Naruto for the right to become Hokage. They fought each other to a standstill which lead to the Uchiha to give up on his desire to lead Konohagakure, though he went on to become a trusted advisor to Naruto. He later married Sakura and father a daughter which they named Sadara.
In the sand village:
Akuma was very, very lost. In his latest battle with Ryu, they had both been flung to different parts of the world. Akuma, dehydrated and on the brink of death, wandered the desert until he came to the sand village, where he finally collapsed from heat exhaustion, and dehydration.
"What the," Kankuro said, looking into the desert. He saw Akuma collapse into the sand, and called for medical ninja.
Kaknuro and the medics ran to where Akuma had collapsed.
"Is he alive?" Kankuro asked.
"Yes sir," a medic said, "But only just."
"So get him on a stretcher!" Kankuro yelled.
The medical ninja loaded the fallen warrior onto a stretcher, and brought him into the sand village.
Two days later:
Akuma suddenly woke up, yelling "You shall fall!"
The situation was explained to him, and was brought into a meeting with the sand village elders, and the kazekage.
"My name is Akuma," Akuma began, "And I travel the world looking for worthy opponents. In my latest battle with my adoptive nephew, we were thrown to different sides of the world. My goal is to get back to settle the score."
"Well," Chiyo, one of the elders, begins, "If you do specalize in fighting powerful enemies, we may have someone for you. We will pay a handsome su-"
"I need no payment," Akuma said, "Fighting is enough."
"Very well," Chiyo says, "The person's name is Sasuke Uchi-"
"Chiyo," Gaara, the young kazekage said, "That's naruto's best friend. We can't just send warriors to kill him."
"I know how you feel about Naruto," Chiyo said, "But he is, unfortunetaly, a political threat and public enemy."
Gaara sighed, "All right."
At the akatsuki hideout, one day later:
Sasuke is training, when he hears footsteps coming from a stone passage leading to the field he's training in. He turns, expecting to see Madara or Kisame, but instead sees a massive man in a jacket with the lseeves just as ripped as his arms. His eyes glow red with menace.
"Who are you?" Sasuke asked.
"My name is Akuma," Akuma replied, "Slayer of gods, the greatest warrior of all time. And I will show you the meaning of pain!"
"Will you really?" Sasuke asks sarcastically.
Immediately, the youth jumped into the air, and sends balls of fire toward Akuma. The god-killer doges, and sends a Gou Hadou Sasuke's way. Sasuke ducks the attack, and rushes Akuma. The two begin a fistfight, with Akuma gaining an edge due to his far superior size. He punches Sasuke in the stomach and sends him flying backwards into a tree. Sasuke recovers, and dodges Akuma's next attack. He charges up a chidori, and rushes Akuma. The god-killer gets caught off guard, and gets an arm slash as he tries to dodge.
The two jump back, and each send a couple of long-range attacks toward each other, all being dodged or blocked. They once again begin to fistfight, and Sasuke manages to get behind akuma, securing his arm around Akuma's neck and pointing the tip of his katana into Akuma's back. Akuma grabs Sasuke and slams into he ground, forcing him to drop his sword. Sasuke jumps up and kicks akuma in the face, breaking his nose.
The two begin to fistfight once more, neither dealing any good blows to each other. Sasuke charges up a chidori, and jumps back. Akuma, thinking it's only a close range weapon, charges at Sasuke, only to get a chidori beam through his hand. This hurts Akuma, but also infuriates him. He screams, and says, "You have sealed your fight, foolish boy."
Sasuke smirks until he sees Akuma transforming into Shin Akuma. Akuma immediately siezes Sauke and starts beating the living hell out of him. Sasuke eventually manages to get away, and says, "Your not the only one who can get upgrades." He then activates his curse mark, and goes second state. His wings/hands grow out of his back, and he flies into the sky. Akuma screams, "Come down and fight like a man!"
Sasuke dives down toward akuma, and clobbers him in the face. Using the distraction, Sasuke grabs his katana, and go's in for the kill. Akuma is more prepared, and grabs the youth's wrist as he dives in. Sasuke manages to get away, but Akuma gets the sword, which he snaps over one knee.
Sasuke flies down and lands about 100 feet away from Akuma, both warriors panting and injured. Sasuke narrows his eyes, and says, "Well, I didn't want to have to do this, but you're just too damn stubborn. AMATERASU!"
Black flames immediately coascle toward Akuma. The god killer leaps into the air, but the flames follow him, setting his foot on fire. He lands on the ground, and...
"KONKU KOKURETSU ZAN!"
Akuma punches the ground, and a shockwave fills the area, pushing away the black flames for a mile away. They immediately again begin to pursue their target, but they are a mile away.
Sasuke is standing there in shock, his jaw dropped. Akuma rushes him, but the akastuki regains his senses and goes for his last resort.
A black avatar begins to envelop Sasuke. First the bones. Then the skin. Then the armor, sword, and shield.
"You now have no chance." Sasuke said, "This shield is impenatrable, and one cut from the sword will send you to an alternate dimension that is the equivalent of hell."
Sasuke advances, all the while the amaterasu racing towards its target. Akuma's eyes widen, and there is always a first time to run. Except for Akuma. His eyes narrow, and teleports behind Sasuke. Sasuke spins around, using the giant's shield to block Akuma's hurricane kick. He slashes, but the god-killer dodges. Akuma once again attacks, but sees something racing toward him; the black flames of Amaterasu. Just then the susanoo sword comes swinging toward him, and to dodge one is to be killed by the other. This the end.
And then the sword dissapears. The Susanoo crumbles. Sasuke had run out of chakra.
Fast as lightning, Akuma bull rushes the exhausted youth, and yells, "SHUN GOKU SASTSU!"
Akuma begins pummeling every scare inch os Sasuke's body. Over 200 bones are broken in about 2 seconds.
Sasuke lies on the floor, and the Amaterasu extinguishes. The youth breathes a rsapy breath. And Akuma positions his foot about a foot over sasuke's neck.
"THIS IS THE WRATH OF THE KILLER OF GODS!"
Akuma was able to crush his foe because he had far superior experience and training, having fought many foes far tougher than Sasuke or anything Sasuke had fought himself, and because Sasuke lacked the raw skill of the master of the Satsui no Hadou.