Jens of the desert

Setsuna was 16 at the start of the series and 21 after the timeskip. Lockon was 27, Sumeragi was 27, Allelujah (or is that the name of the psycho personality?) started as 18 and I believe Tieria was SUPPOSED to be phyiscally 16. Wang Liu Mei was 17 at the beginning and seeing as how Saji and Louise were university students in the first season, they were probably 18. The strange thing though, Feldt