When Sasuke was little, his brother's mass murder of their clan broke his heart and nearly froze it. When Itachi returned to Konoha again years later to capture Naruto, Sasuke tried to kill him. The young raven was easily, humiliatingly defeated. Sasuke's shouting of wanting his brother dead and reviving his clan gave Itachi a chance to crush his dreams once again. “Foolish little brother. Our clan is finished, unrevivable. You will always be alone. Uchiha women are the only ones that can carry our seed. It’s hopeless.” He had never actually met an Uchiha that was not born one before the massacre and he had never bothered to think about why. Itachi had taken the family he had and then cursed him to live and die alone with no hope of another family of his own. Ever. There would be no winning for Sasuke in the end, no taking back of what was stolen. Itachi’s death was the only thing he had to look forward to.
He had wondered if Naruto had heard Itachi tell him this. Would he tell Sakura ? Once she bothered to know him she had been able to see what was in his heart when he was trying desperately to lose it. He warred with himself to avoid her. Her loving him was more than annoying then. It was agony. Her presence was always throwing what he couldn’t have in his face. He was alone, always would be alone, would doom any woman he loved to be childless. After what he had lost, he could not do that to someone else. He was better than his evil brother. This kept him away from anyone he could care about, far enough to reject if they got too close. Despite his best effort to accept his fate and give up his desire for love, he couldn’t help loving Sakura back. He knew she would accept anything for him. For a while anyway, until the passion cooled and regret came to steal her heart away. He wouldn’t tell her. It was better to never lose it, to just enjoy it as it was. At least she had given him a glimpse of what it would have felt like. He thanked her for that. He had to.
When he saw Sakura again at the hideout his hormones had kicked in and he ached. Her sweet eyes, something broke behind them when he threatened Naruto. The two of them had obviously grown closer. It burned him inside. He knew then he had to stay away from her. He would go mad with jealousy. Part of him had always seen her as his, never really believed she would belong to someone else.
Naruto would be adored. Love would be so easy for him. Just another way he would lose to the jinchuriki. Something he could never be strong enough to remedy. If he didn’t have to see it happen while he sat on the sidelines he could be happy for them, but they chased him down. At the time it enraged him. Did they know he was too weak to love them up close? Were they trying to force him to admit it? His only other option was pushing them away. Or just killing them. He hoped they would give up on him .
Sasuke silently cried himself to sleep that night for the first time in many years and awoke to find Orochimaru’s tongue wrapped around his shaft, his snake eyes locked on the raven haired boy knowingly. He laid back and let him.This was his life now. He let the Sannin run experiments to see if he could breed with non Uchiha.They all died within weeks. Karin kept begging him to lay with her, but he saw no good reason for her death until Danzo took her hostage.
When Sakura came to kill him he had been certain she had given her heart to someone else. How could she do this if that was not the case? It must be Naruto. He could sever this. Naruto would hate him and stop trying to bring him back and no one would have her. All he wanted was to be left alone and not taunted, avenge his clan that would be wiped off the earth too soon by their village. He moved to strike her and it was Kakashi who stepped in and saved her.The way the Copy Nin looked at her, the pain and fear in his voice as he begged Sasuke not to kill her… there was no guessing needed anymore. While Sasuke was attempting to delude himself regularly, he was unfortunately very self aware. He knew Naruto was the better man, but he also knew Sakura. She was a girl highly subject to her instincts and would have a hard time devoting herself to someone she didn’t melt inside for. It had been comforting to think that even if she was with Naruto and he made her happy that Sasuke could make her drop her panties for him anyway and put her in a thrall. With Kakashi as competition though...his place in her fantasies was under a real threat. He felt like his family, the one he could only pretend to have in the future, had been stolen too. Everything was truly gone then. The nights he felt regret and missed them was all for naught. It was over and he wanted to burn the world down.
After his fight with Itachi against Kabuto, he’d shoved his hand in a pocket and found a slip of parchment and his brother’s bonding necklace. On the slip was Itachi’s neat script :”It’s not over. Summon the scroll .” He bit his finger, made the signs, and opened the resulting scroll. There he found hope. The Hatake clan was a bridge for mating with non-Uchiha. He would overthrow Konoha and take his bride. He could force the Copy Nin into the contract of bonding to save her life once Kakashi had nothing else left to be loyal to.