Square Enix has just announced Dissidia duodecim prologus Final Fantasy a spin-off of forthcoming franchise spin-off Dissidia 012[duodecim] Final Fantasy.
According to the European PlayStation Blog, it's a brief pre-amble to Square's brawler that introduces Final Fantasy XIII protagonist Lightning to the series for the first time. You'll get to play through a unique scenario that recounts the events leading up to Dissidia 012[duodecim] proper.
No European release date has been confirmed yet, but it will be available in the US on 15th March for $2.99.
Those purchasing the add-on will also unlock Final Fantasy VII's Aerith for use as an assist character in the full game and any items you pick up in the download will carry over too.
Dissidia 012[duodecim] Final Fantasy launches on PSP on 25th March.