One moment Sasuke is sitting around his campfire, the slightly chilly night quiet around him, his sharingan activated as he stared into the flames, memories flashing before his eyes, and then the next thing he knows he's standing in his childhood home, four sets of startled eyes staring at him.
He doesn't move, even when his mother's tanto is suddenly pressed against his neck. Fugaku is staring at him, his eyes hard and unforgiving and Sasuke can see Itachi in the corner of his eye, kunai poised and ready to strike him if he so much as moved in a way Itachi didn't like.
It's seeing a younger version of himself, wide-eyed and staring at Sasuke from behind his father, that keeps Sasuke from lashing out.
"State your name and your purpose, intruder," Fugaku demands, his hand reaching down to push the younger Sasuke farther behind him, trying to keep the young boy from gaining his attention.
Sasuke takes his family in, calmly, and silently curses his family's legacy.
The Jikan Phenomenon is something that the Uchiha rarely talk about. The sharingan and it's capabilities when it comes to space and time are largely unexplored. The sharingan has many techniques that, with enough training, the wielder can control. The Jikan Phenomenon is not one of them.
The entire basis of the phenomenon happened so long ago that the Uchiha Clan no longer remembers the first incident, only that it started a domino effect. Once it happened, it would continue to happen for decades to follow. The premise is simple: the sharingan takes its wielder back in time with not forewarning whatsoever. Sasuke doesn't remember it happening a lot when he was younger, maybe once or twice, but with the clan massacred as they were, there was never an opportunity for anyone to just come back by chance. Now that Sasuke thinks about it, it was a rather foreboding sign that something was going wrong towards the end of the Uchiha Clan's existence.
"Speak, intruder," Mikoto's voice breaks his train of thought, her tanto pressing tighter against his throat, the overt threat hard against his skin.
"Jikan," Sasuke replies eventually, eyeing his family.
There's a pause from everyone around him, gazes met and exchanged, before the tanto leaves his throat and Fugaku is motioning towards the doorway that would lead to the hall outside of the kitchen. "Follow me."
Sasuke stays silent as the two adults eye him warily. Sasuke isn't quite sure how to handle seeing his family again. There's so much pain surrounding his past, surrounding the images of his mother and father, that Sasuke is doing his utmost to try and distance himself slightly from the two in front of him. If he thinks of them as his parents, he might break down. Sasuke has long gotten over his loss, but that doesn't mean the wounds still aren't there.
"How far into the future do you come from?" Fugaku asks, his expression blank except for the tiny hint of curiosity sparking in his eyes.
Sasuke tilts his head, quick calculations flying through his mind, as he tried to adjust his thinking. This is clearly before the massacre, before everything went wrong, and his younger self had looked so incredibly young when he'd gotten the brief glimpse of him before. He struggles with himself slightly before he quietly replies, "More than ten years."
Mikoto and Fugaku exchange another glance, communicating with each other without even saying a word, before they once more turn back to him, scrutinizing his appearance and demeanor. Mikoto is watching him incredibly closely, an odd expression on her face. Both of the shinobi in front of him have already clocked into the fact that he never said his name and it looks like Mikoto is slowly putting the pieces together. If anyone was going to realize who he was without him having to introduce himself, it would either be his mother or Itachi. Speaking of Itachi, Sasuke has to keep himself from smiling fondly at the silent presence at his back. The young Itachi is standing silently behind him, guarding the door from both his escape and from anyone trying to get in before it is deemed necessary.
"You never mentioned your name," Mikoto finally states, breaking the quiet that had descended upon them.
Sasuke can go in two different directions. He can lie, tell them he's some random Uchiha from the future, let them think that the clan is going strong. Let them make their own decisions and let the rightful history of his past take place. Let the massacre happen, let his younger self suffer for years before being beat into sanity by Naruto's fists and words. He can let Itachi make his mistakes and let him die, just as his future self had wanted.
Sasuke has the choice to stick to his past, his future, and to let things exist as they had.
Or, he could tear apart his future and make a better one.
The Jikan Phenomenon, after all, didn't only deal with time. It also dealt with reality. When an Uchiha went back in time and changed nothing, met no one, they would eventually be carried back to their future, everything the same just as they left it. When the wielder made the decision to change things, however, it became more complicated. Every decision everyone makes allows time to branch off and make a new reality. A new dimension. The Uchiha were the cause of several shifted and newly formed dimensions. If Sasuke spoke up, if he told them the truth of who he was and where he came from, his machinations would cause a shift. A new reality, a new dimension would be created alongside his own. A dimensions where things would be different.
The only downside being that if his past changed, his connection to his own reality would be severed. Sasuke's sharingan would not be able to connect to his future because his future would no longer exist in the reality he was a part of. He would be stuck in the past of a dimension that he had created.
"My name is Uchiha Sasuke."
He mourned all those he was leaving. He mourned Kakashi, his sensei who was so very tired. He mourned Sakura, the girl who he so hastily discarded as weak. He mourned Naruto, the boy who never gave up as he pursued Sasuke to hell and back. He would miss his team, his future family. But, Sasuke had many mistakes and held plenty of regrets, and if he didn't take this opportunity, he would never forgive himself. The Jikan Phenomenon only happened once to a select few and Sasuke needed to make sure that there was more Uchiha for the phenomenon to happen to.
He held the memory of his found family close as he wished them goodbye, finally meeting the shocked gazes of his past nightmares, and now possible redemption figures.
"There's some things you need to know."