Every character, even returning ones, have at least three costumes in Dissidia 012[duodecim]: Final Fantasy. There is original form, another form, and an all-new third form. V-Jump gives us a look at four third form outfits.
Final Fantasy VII villain Sephiroth has an unaltered, original costume for his third form. Cloud has a costume designed by series artist Yoshitaka Amano. Golbez from Final Fantasy IV has an outfit from Final Fantasy IV: The After Years. Cecil’s third form costume is based on the Final Fantasy IV DS remake.
V-Jump also has new information about the assist system where players can call out a partner character for a brave damaging or HP damaging attack. Hit your opponent’s assist character during an assist attack to trigger an assist lock. This prevents your opponent from using an assist for a period of time. As a comeback move, Square Enix created the assist charge system. If you’re in a pinch with low HP and successfully counter an attack you’ll get one full assist bar. That’s good enough to do a brave attack with L + O.