Brave Sword (勇者の剣 Yūsha no Ken, Hero Sword in the Japanese version) is a B-Rank sword used in several Fire Emblem games. It is among the Brave series of weapons. It is usually found in the middle or end of the game. Like all other Brave weapons, it gives you 2x your ordinary hits, which potentially allows you to do a quadruple strike.
The brave sword is a powerful and well-rounded sword with substantial durability and decent accuracy. The brave sword gives a tactical edge to any unit that wields it because of the fact that can strike consecutively. This is a good weapon for slow units like generals and armor swords to use so that they can attack twice. This is also a good weapon to use to train units, and it is also tactical to use when attacking a powerful unit when a counterattack is not worth the risk. This ability is also favored in forged weapons on WiFi in Fire Emblem: Shadow Dragon.
The only true drawback to brave weapons is that since they strike so many times, that durability decreases very fast. As well, they can tend to be on the heavier side when it comes to swords.
In Fire Emblem: Genealogy of the Holy War, the Hero Sword is given to Ayra by either Holyn or Lex in chapter 3. If Ayra's Hero Sword is not passed down to second generation, it can be found on Coruta in Chapter 8. It is also given to Seliph by Patty in Chapter 7.
The Brave Sword is a sword best used for Myrmidons and Swordmasters. Of course, any unit (even slower ones) can use Speedwings to improve their speed and have an increased chance for 4x the strike opportunities. A good strategy for brave weapons is to save them for the final battle or for an exceptionally hard enemy unit (usually a boss like Ena or Bryce) because the sword's durability decreases rapidly (they typically have 30 uses).
In Radiant Dawn, Trueblades can attack a total of 8 consecutive times by using the Skill Adept, a Brave Sword, and having 4 or more Attack Speed higher than the opponent. With the Mastery SkillAstra, it is possible to link up 20 consecutive attacks.
This is possible because:
Having 4 or higher Attack Speed than the enemy doubles your hits to 2