Dread Dragon Slayer

Beat the battlefield "The Rank 2 Final Mission" at Horlais Peak.

This battlefield is available to those who have advanced to the appropriate part of Bastok Mission 2-3 The Emissary and chosen the Windurst > San d'Oria route, or Windurst Mission 2-3 The Three Kingdoms and chosen the Bastok > San d'Oria route. If you have completed both of these missions and had chosen the other routes, though the missions themselves aren't repeatable, you may still enter the battlefield if your party leader undertakes it.