Direct Text from Devil May cry wiki.
The Yamato once belonged to Vergil's father, Sparda, and according to the Order of the Sword, it was used to seal the "true Hell Gate". It was eventually given to Vergil as a memento, and he uses it as his primary weapon in Devil May Cry 3. It was somehow found, broken, by the Order of the Sword, and their act of taking it is what drives Dante to retrieve it by entering Fortuna in Devil May Cry 4. It is kept in Agnus's Containment Room within Fortuna Castle, but is restored and taken by Nero when his dormant powers as an heir to Sparda emerge. Thereafter, Nero is able to use the sword while in Devil Trigger. However, it is taken back from him by Sanctus when he is absorbed into the Savior, and is then used by Agnus to reopen the Hell Gate. After slaying Agnus, Dante retrieves the Yamato from the gate, which he destroys with it. Thereafter, he wields it while his Dark Slayer Style. While fighting the Savior, Dante uses it to free Nero, and gives it back to him. At the end of the game, Dante charges Nero with
