Naruto: Clash of Ninja/Sharingan Kakashi

The Sharingan given to him by Obito is a sticking point to Kakashi's fame in the Naruto world. Granting him the ability to mimic the movements and jutsu of others, the Sharingan gives him an edge in battle by allowing him to turn his opponent's abilities against them. This has allowed him to add over one thousand different attacks to his repertoire, leading to his nickname of "Copy Ninja Kakashi". Because the Sharingan only naturally occurs in those of Uchiha lineage, and because his is always active, Kakashi depletes his energy quickly when using it and so must cover it with his headband during his daily activities.