Chapter 24C: Days Lost

In this mission, you have to go through colored doors to avoid the traps. These doors can only be opened by characters with locktouch (or door keys dropped by certain enemies) and there are chests as well so bring at least two to help you. Opening the red doors will trigger an explosion in the immediate area, damaging everyone so might as well avoid them. Make sure to save before opening a door, just to be sure.

If you initiate a battle with the first Vallite soldier, more reinforcements will appear from all directions. The vallite soldier in the first room will move but as long as you stay out of his range, he won't be able to notify the others. That said, always display the enemy's attack range so you can stay out of it. High movement range units will allow you to outpace the soldier, should you decide to avoid him.

Open the first blue door to reveal the next room. This has a chest containing an Enfeeble in a small room in the middle. If you'll go after the chest, you'll be forced to fight since whoever will loot the chest will be within attack range. The reinforcements in the second room is just a handful so deal with the nearest ones before moving to the next blue door.

After opening the blue door, Mikoto will tell you that the last door that you should open is the red one. Ignore this tip and remember to still open the blue door. This room has three chests, two in the NW corner and one in the SE corner. Both are guarded so it's inevitable fighting them if you wish to loot the chests.

Chest contents:

NW: Surefire Yumi, Flame Shuriken

SE: Lightning

If you have no choice, you can have some of your stronger units hold off the bottleneck and defeat any pursuers. Make sure they have ample healing, preferably someone with area-of-effect skills and healing with Azura's Amaterasu skill. After collecting the loot, regroup everyone then head to the last door and open the blue door again to locate Mikoto's doppelganger. Opening the red door will trigger an explosion that will deal 99 damage to everyone, while also exposing you to several enemies ready to attack. Defeat the remaining enemies in that room until you're able to reach and defeat Mikoto.