7. Trails in the Sky the 3rd
Trails in the Sky the 3rd is the most different game in the entire series, outside of Nayuta, of course. The game opens following Father Kevin Graham and Sister Ries Argent of the Septian Church.
Unlike the more traditional RPG design of the previous games, The 3rd is a dungeon crawler that traps most of the important characters from the Trails in the Sky games in an alternate realm.
Despite the change in style, The 3rd is still a great game, with some fantastic storytelling that helps tie loose threads together, give background on party members, and hints about the future. For example, this is the first game that we meet Gilliath Osborne, a hugely important character in the Cold Steel games.
The 3rd also has the best final dungeon of the franchise, forcing you to utilize each and every party member.