Lucas was cut off from his senses. It was like a void of all things but somehow his mind held on. To kerp his sanity he recounted his life's memories. Most importantly the ones that made him happy. He did include the ones where things went wrong and how he wished he could have changed them. For example he could have called his mom the day of the crash. He could have tried to focus more in classes. While it's meaningless now just the imagination of him finding success was enough to make him fell happy even if it never happened.
This occurred for what felt like what could have been years. But perhaps it was only days Lucas couldn't tell. Perhaps he should have started counting like that Senku character from that one anime he watched, Dr. Stone. 'Damn it I may be smart but there are some things not even I could think of. Too late now I guess.' Truthfully Lucas knew that if he spent his time counting instead of keeping hold of his memories he'd probably have went insane by now. Instead he began to remember his life again in chronological order he even included the memories of his favorite TV shows he watched this time. Some were more forgettable. This time he couldn't even recount what happened in that one anime about the dude being reincarnated with his cellphone. It was a shitty anime anyway.
Suddenly another pair of memories tried to override his. At one moment he was recalling his time in university and the next it was about his time in a ninja academy. 'These aren't my memories'. He then went back it was when he saw his family… non someone else's family get massacred right before his eyes. 'Wait is that itachi. I must be remembering that anime Naruto, but why is it so vivid. It's like it actually happened to me and not from across a screen.' The two memories fought for dominance but Lucas won out. He simply had more memories. It was more of a struggle than you would expect however. Despite Lucas having more memories it was Like Sasuke's were more potent.
The end result had a strange effect where Lucas became Sasuke and Sasuke became Lucas. It was sort of like how Lucas imagined fusion would work in dragon ball but only on the level of a soul but not including the body. A better example would be a Yamanaka mind transfer but both minds fused and that fusion was permanent.
There was no loser in this exchange since they both combined thier memories. With this combination Lucas obtained the most recent memories as well as the subconscious ones that came from Sasuke's training. His coordination. What language to speak, which seemed to be Japanese. The most recent thing he learned was how to climb trees with chakra. After that he had gotten into a battle with the Ice release ninja named Haku on the bridge that his client Tazuna was building. In this fight Sasuke eas trapped in an Ice mirror which Naruto stupidly jumped into. Sacraficing himself took a seemingly fatal blow to protect Naruto awakening the sharingan just before he died… or so Sasuke thought.
Lucas or rather Sasuke now felt his eyes began to twitch and sensation began to return to him. The void had disappeared and he could feel the rough texture of the bridge beneath him.
Opening his eyes he could see Sakura crying over him and the fog lifting from the bridge.
"Sakura, I'm not dead stop crying. Also get off me your arms heavy." Sasuke woke up to the sun of being a human pincushion.
The tears still freely flowing down Sakura's face as she noticed that I spoke. She looked at Sasuke and noticed he was the one who spoke. "Sasuke!" Ignoring what Sasuke said she went in for a deeper hug. Sasuke couldn't blame her too much she was probably traumatized. It's not like he could move to pudge her off either so he put up with it for a bit longer. Before finding the strength to get up.
'This world really is real.' Sasuke looked around Ewing the dead bodies of Zabuza, Haku, and Gato along with several of his gaurds. Unaware of his shringan turning on this scrn was imprinted in his mind forever. It wasn't long until he spotted Naruto and Kakashi. Looking back he could see the villagers rallying to defend the bridge. Kakashi proceeded to make a couple dozen shadow clones. This was enough to get the thugs to retreat leaving. thier dead boss behind.
It began to snow not long after as Kakashi carried Zabuza's body closer to Haku as per his last request.
While Naruto mourned the deaths of Haku and Zabuza the cruel reality of this world really began to set into Sasuke's mind. His other half wasn't used to the cruelty of the ninja world. While they both remembered the Uchiha massacre it was more Sasuke's memory than one from Lucas. With two minds in one head it somewhat diluted how traumatic that memory was sense for the half of Lucas it seemed more like a nightmare than reality. Now however he can only see it as it was. Just Haku and Zabuza had died so did the Uchiha. This world could truly be cruel.
'I should have been more specific. I wish I could have been the main character in romance anime. Bring me to Kaguya sama damn it.' Sasuke couldn't help but feel slighted by his bad luck. "Hn".
Looking around he seen no trucks around. 'No more isekai'd today it seems.' Little did he know Haku was a journey of his own at the moment. Haku was more blessed by the reincarnation police as he got the ultimate reincarnation. He was reborn as the main character in DXD. Lucky bastard.