A possible plot is that the OC with the blue sharingan wakes up with no memory but this strange power. They start to piece together their past as they encounter various characters from the Naruto universe. As they do so, they realize that their blue sharingan holds the key to a long - forgotten prophecy. They must then decide whether to embrace their role in the prophecy or try to avoid it, all while dealing with the usual ninja - related threats like battles, rivalries, and political intrigue in the ninja villages.
Maybe the plot is about an OC who discovers their blue sharingan has a connection to an ancient and powerful artifact. As they explore this connection, they are hunted by dark forces who want to use the artifact for evil. Along the way, they form alliances with other characters and learn to master their sharingan's power to protect the artifact and the world. It could also be a plot where the OC's blue sharingan is a result of a forbidden experiment, and they are on the run from those who conducted the experiment while trying to understand and control their new - found power.