In these fanfictions, the 'cheat' is usually something that gives the reincarnated character an unfair advantage. It could be a special skill, like instant language learning or the ability to copy any magic spell. It might also be an item, like a magical ring that boosts all stats. Basically, it allows the character to bypass normal limitations and progress much faster than normal characters in the story.
One popular theme is overpowered abilities. The protagonist often reincarnates with some sort of cheat ability like super strength, magic that defies the normal rules, or an incredible intellect. Another theme is revenge. They might have been wronged in their past life and use their new - found cheats to get back at those who wronged them. Also, harem or multiple romantic interests can be a theme, where the protagonist, with their cheats, attracts many characters romantically.
He could be reincarnated as one of the Uchiha clan members. This would be really interesting as he would have to deal with the Sharingan and the Uchiha's history. He might even change the fate of the clan.
Well, it's hard to say. Fanfiction can vary greatly. Sometimes authors might introduce such plotlines for drama or character development. But without knowing the exact fanfic, it's impossible to give a definite answer.
Batman is quite popular. Reincarnating as him gives the character a chance to have all his gadgets and detective skills. Also, Superman is a common choice. Having his superpowers and being able to fly around Metropolis would be exciting. Wonder Woman is another one. Her connection to the Amazonian culture and her superhuman abilities make for great fanfiction material.
"I recommend" The Godly Doctor's Pet ". This novel is a fantasy romance-Oriental fantasy novel. It tells the story of the female protagonist being a descendant of Shennong. Not only is her medical skills unparalleled, but she also has a rare treasure. She had risen to prominence, summoned against the heavens, and used all kinds of forbidden spells. The male lead was a handsome but strangely blind black-bellied hidden prince. In the transmigration, the female protagonist became a little waste who was abandoned by her family. However, she relied on her cheat and medical skills to gradually rise and began a complicated emotional entanglement with the male protagonist. I hope you like this fairy's recommendation. Muah ~😗
Harry Potter himself is a popular choice. Writers often explore what would happen if someone else's soul was in Harry's body and how that would change the story. Hermione Granger is also a common one. Reincarnating as her gives the chance to delve deeper into her intelligence and how she could use it in different ways. Another popular character to be reincarnated as is Draco Malfoy. It allows for a different perspective on the Slytherin house and the Malfoy family's role in the wizarding world.
Sakura also often appears. She might be confused by the changed behavior of the reincarnated Sasuke. Maybe the reincarnated Sasuke is more open and friendly towards her than the original Sasuke, which would lead to different interactions between them.
Aether and Lumine are quite popular choices. Since they are the main protagonists in the original game, many fanfiction writers like to explore what it would be like if someone was reincarnated as them, perhaps with different personalities or goals. It gives a fresh perspective on the main storyline.
Jon Snow is quite popular. People like to be reincarnated as him because he has a lot of potential for growth and a mysterious backstory. They can use their new knowledge to perhaps avoid some of his tragedies and rise to power more quickly.