Yes, there might be such fanfics in the Naruto fanfic community. Some fans like to create unique family relationships in their stories, and making Naruto and Shisui brothers is an interesting concept that could lead to many different plotlines and character interactions.
In fanfiction, Shisui's Sharingan often has some unique abilities. It's usually depicted as having powerful genjutsu - related powers. For example, it might be able to cast illusions on multiple opponents at once with greater ease compared to a normal Sharingan. His Sharingan can also potentially be used to transfer memories in more creative ways in fan stories, like not just the basic memory transfer we saw in the original Naruto series but perhaps more complex emotional and skill - based memories.
Sakura's amusement could actually make Shisui more likely to continue annoying Itachi. Since she finds it funny, Shisui might see it as a sign that his actions are acceptable and entertaining. This could potentially strain the relationship between Shisui and Itachi further if Itachi doesn't like being the target of Shisui's annoyance.
Liu Shisui and Liu Ci were two different people. Liu Shisui was a character in the " The Great Path Toward Heaven ", and he was Jing Jiu's disciple, who belonged to the Green Mountain Sect. He was described as intelligent, kind, and had a determined temperament. Liu Ci was the Sect Master of the Green Mountain Sect, and was called the Immortal Liu Ci. Although both of them were related to the Green Mountain Sect, they played different roles. The search results did not provide any clear information about their relationship. Therefore, there was no definite conclusion about the relationship between Liu Shisui and Liu Ci.
In some fanfictions, Shisui's Sharingan has a different color or pattern. This is a simple but effective way to make it stand out. For example, it could be a deeper red or have an extra swirl in the pattern.
In this kind of fanfiction, Naruto might obtain Shisui's brother's Sharingan through some unforeseen events. Maybe Shisui's brother sacrifices himself and entrusts his Sharingan to Naruto. As for new abilities, it could enhance Naruto's perception skills like being able to see through genjutsu more easily and also improve his combat awareness in battles.
There was no clear description of Liu Shisui's final result in the game " The Way to Heaven ". There was no mention of Liu Shisui's fate or ending in the search results. Therefore, they couldn't know Liu Shisui's final result.
Another one is 'Itachi and Shisui: The Untold Tales'. This story weaves in some unique scenarios that might not have been explored in the original series. It shows their interactions with other characters from a different perspective, highlighting their strong bond.