Square Enix has, via Jump Magazine in Japan, revealed the Laguna Loire from Final Fantasy VIII will be the fifth character to join the ever expanding cast in Dissidia Duodecim: Final Fantasy.
The other four characters that have been confirmed so far are Lightning, Tifa Lockhart, Vaan and Kain Highwind. However, Square Enix said there could be up to 10 new characters.
Dissidia: Duodecim was recently announced for a Spring 2011 release in Europe exclusively on the PlayStation Portable.
Source: Final Fantasy Union