After arriving in Nestra, a mysterious singer attacks King Garon with song, and the Hoshidan army attacks.
Defeat the Boss
The objective is to defeat the boss unit, an Oni Savage in the northeast corner of the map.
There are two chests: one on stage, and one in the southeast part of the map. One of the shrine maidens will drop a Chest Key. You can bring a Ninja or Outlaw to open the other chest, since you only get one Chest Key. The chest on stage contains a Seraph Robe, and the southern chest contains 10000 G.
There is a path to the stage on the left, and another on the right.
In the southwest part of the map, there is an ally unit. Be sure to send Corrin down to talk to him, and he will join you.
The Shrine Maidens in the eastern part of the map can inflict Silence and Freeze on your units, so be aware of their Staff ranges.
The narrow pathways of this map will slow down your non-flying units. There are going to be quite a few flying enemies, including some flying reinforcements that show up after about seven turns. Niles will be very helpful against these with his bow.
The boss unit won't move or attack until you enter its range. It can do ranged attacks, so be careful where you put your units.