In this chapter, you have to either escape within 20 turns or defeat the boss. The map is divided to two areas inaccessible from each other. The escape point is to the far east of the northern island while the boss is located in the far west of the southern island. Since you can’t send anyone there, you’ll have to use the only dragon vein in the area, the one to the west of the northern island which will create replicas of all your units in the southern island. It’s worth clearing the southern area since there are a lot of enemies there with loot that you can collect. You can only bring 8 units in this battle so it’s important to bring your key and strongest characters.
At the start of the turn, start heading west first and clear the enemies so you can activate the dragon vein. Your original group can’t pass the lake in the middle of the northern island so you have no choice but to fight your way down south around the lake and chasm. Once activated, your replicas will start in a safe area with healtile. Command abilities like Azura’s Sing will not be available for the replicas nor the relationship boosts by supporting each other. Take note that if the original unit has been defeated, the replica will disappear as well.
You can pair your units there and keep your healers out of enemy reach. I recommend waiting for your enemies to come to you during the first turn then move out when you’ve cut down the incoming aggressive units’ numbers. At the end of the fourth and sixth turns, more reinforcements will appear near the boss in the southern island. These reinforcements doesn’t drop anything so engaging them won’t be unless they’re blocking your path.
Keep pushing your units on both islands. In case you cleared the northern island first and you have a lot of turns left to escape, don’t have any of your units escape yet if you’re planning to clear the southern island. Escaping will remove the replica as well so don’t escape with any of your units until you’re done defeating the southern forces with loot. Once you defeat the boss or escape with all your northern units, the chapter will be complete.