The Dawnbringer is a legendary sword forged long before the time of ponies, even before Princess Celestia's birth. It is the brother sword of the Dawnbringer.
The Dawnbreaker's history is almost completely unknown. There are little to no reports on it before, during or after its creation. As far as history goes, it doesn't exist. It only appeared during the present day when wielded by Dreamcast.
The Dawnbreaker is described to be able to destroy any and all light absolutely. Any kind of light magic that the sword comes into contact with is immediately destroyed, with absolutely no trace of it left. It is also able to ward off any light by outputting a field of energy around the sword and user. The sword is completely indestructible by any means, and it cannot be scratched, chipped, or snapped by anything and cannot rust and be tarnished by blood or dirt. or anything else. Unlike the Dawnbringer, the Dawnbreaker does not go into a state of dormancy when not used for long periods of time. The sword also has the ability to sync with the user if the user has enough power, and gains an exponential increase to its abilities when it does. It has the ability to destroy souls and erase living beings from existence.
It is one of the very few things that can kill Lightblade.
The Dawnbreaker bears the exact same appearance as the Dawnbringer, being a silver colored longsword measuring 2.25 ft in length and 3.5 cm in width, however the handle is black in color and has a red unknown gem in the hilt. The crossguard bears a shape similar to demon wings. The blade takes on a red aura, and this aura is the key to its light destroying ability, and the field itself cannot be broken or disrupted by anything other than its brother sword, the Dawnbringer. When in perfect sync with the user, the blade turns black and takes on a darker red aura. The metal used to make this sword is an unknown material that is both light and indestructable by normal means.