It's ok if you forgot Final Fantasy: Airborne Brigade was a thing; I did, too! The mobile social game is kicking off a special event in Japan today, however, and it's a crossover with Final Fantasy VII: Advent Children.
It's unclear whether or not the North American version will also take part in the Cloudy Wolf event, but it adds Sephiroth to the game, and allows players to upgrade Cloud's Omnislash Limit Break from UR rank to SSR rank. Also, casting Legend Summon Cloud ten times will permanently grant you SSR rank Cloud.
A Cloudy Wolf quiz is part of the event, as well. Players who answer all of the questions correctly will receive over 100 medals.
Final Fantasy: Airborne Brigade is available for both iOS and Android devices. For those unfamiliar with it, the game lets you team up with friends on a quest to restore light to the kingdom's last guardian crystal, and features little Theatrhythm styled peeps. You can collect cards featuring FF characters, battle bosses, explore areas, and compete to become the top brigade. Does anyone here play this?