Gaiden levels are extra missions or Side Quests, gained by fulling a certain requirement to the chapter before it.
Upon completing these Gaiden chapters you will obtain a Legendary weapon.
Gaiden Chapter
How to unlock
8x
Complete chatper 8 and keep Lillina alive
12x
Complete chapter 12 under 20 turns
14x
Complete chapter 14 in under 25 turns
16x
Keep Douglas alive in chapter 16
20Ax
Complete 20A under 25 turns, and recruit Dayan and keep him alive
20Bx
Complete 20B under 25 turns, and recruit Yunno and keep her alive
21x
Beat chapter 21 in 30 turns. You must use Fa, and keep her alive.
