Sasuke Uchiha's Hand Forged Katana from Naruto, Refurbished

Additionally, as a member of the Uchiha clan, he inherits the clan's Kekkei Genkai (or bloodline trait): the Sharingan. He begins to unlock it in the fight with Haku (who himself was using a Kekkei Genkai) and gradually gains strength as he learns to use it to track movement and observe ninjitsu techniques. It helps to have an airhead like Naruto as a teammate. At first he doesn't like Naruto, but as they and Sakura learn to work as a team, he shows a surprising willingness to protect Naruto. It is the beginning of a rather complex partner/rival relationship, since each looks out for the other but at the same time wants to be better than the other. When Sasuke fought Naruto, they each use a powerful jutsu. Naruto uses Rasengen and Sasuke uses Chidori. Chidori, also known as Raikiri (lightning blade), is a jutsu taught to him by Kakashi.

*That sword is the one Sasuke carries after leaving the Leaf Village to train with Orochimaru, one of the main anatganists in the series. Sasuke seeks to kill his older brother to get revenge when Itachi (Sasuke's brother) went berserk and murdered the entire Uchiha clan except for him and Sasuke. After two years with Orochimaru, Sasuke killed him when he realized that he had surpassed his master and no longer needed him. After that, we see him charging, but rarely using the sword. Though this is probably due to the fact that we've only seen a little bit of what happened to Sasuke after he formed a team to help him track down his brother.