Still three games left unguessed
#24
-Final part of the Erebonia arc...
-...which follows the Liberl arc...
-...and is happening concurrently with the Crosbell arc.
#22
-Set in a kingdom once ruled by The Pale King
-Features several different endings, but the true ending can only be achieved by unveiling the source of the sickness plaguing the kingdom
-The source is The Radiance
#21
-Picks up a month after the previous game, with the main character finding himself in the middle of a civil war between the Noble Alliance and the Imperialists
-The first part of the game consists of you traveling around the empire searching for your companions from the previous game
-The same series as #21