The Twilight Bracelet is the rare hack item given to Kite in the video games and anime series of .hack. It has the power to rewrite data in the game The World but harbors consequences of corrupting the player, namely Kite.
The Twilight Bracelet is an item that was made by Aura in order to stop Morganna and the 8 Phases from destroying The World and its players. The item is first introduced in .hack//Infection as players Orca and Kite encounter Aura at the bottom of a beginner's dungeon as Aura presents the Book of Twilight to Orca, claiming that its power can save or destroy The World. Immediately after, the two players encounter the Terror of Death, Skeith,who was pursuing Aura. Aura flees and Orca engages Skeith in combat, surprised that none of his attacks do any damage. Orca is quickly defeated and Data Drained by Skeith's own version of the Twilight Bracelet and just before Kite is attacked, hacker Helba interferes and teleports Kite away, the Book of Twilight transfering to his character.
With the book still in tow and Orca in a coma, Kite set off to find some answers only to encounter Blackrose, who insists that he come with her to Hidden Forbidden Holy Ground, where a cathedral is located. The two novice players observe a statute that looks like Aura and are attacked by a high level monster. Balmung comes to save them, but the monster becomes corrupted. Wondering what to do, Kite hears the voice of Aura as the Book of Twilight activates, changing Kite's outfit from green to red and bestowing him with the Twilight Bracelet. He fixes the enemy and Balmung defeats the monster, wary that only hackers could do something like what Kite did.
As the game progresses, the character finds that the two main uses of the Twilgith Bracelet are Data Drain and Gate Hacking. Gate Hacking is used when an area of The World is locked and with the use of Virus Cores, Kite can transport his party through the block. Data Drain allows Kite to turn corrupted monsters back into their original forms, only beatable. However, normal monsters can be Drained in exchange for less experience points but with chances of rarer items and virus cores. The consequence of Data Draining though is Corruption as the constant rewritting of data causes Kite's character to get weaker. 100% corruption usually leads to Kite's demiseand game over, but can be reversed for every monster Kite and his party defeats without using Data Drain.
Only certain players can see the Twilight Bracelet due to its nature. Hackers can identify it as a bracelet, such as Helba, and corrupted AI like Mia and the possesor, namely Kite. Other players are unable to see it in a dormant stage unless Kite uses Data Drain or Gate Hacking, which causes the bracelet to appear. Mistral even beckons Kite to take her to a dungeon just so she can see it again.
The bracelet does not last forever though as during a fight with the seventh part of the Phase, Tarvos, the bracelet broke. Kite realized that while the bracelet got stronger with each Phase defeated, a monster called Cubia also became stronger because it fed off the power of the bracelet. During the final fight with Cubia, Kite ensured that the bracelet would be destroyed altogether, meaning that Cubia would die too.