Yoshitaka Amano contributed a lot of artwork for the game. Amano is the Final Fantasy series's iconic illustrator who has designed numerous logos, characters and monsters for the games.
Some of the game's artwork has been published in Final Fantasy Brave Exvius The Art Works book.
Sprite concept art
Trio versus Black Dragon.
Artwork celebrating the upcoming 2nd Anniversary of FFBE.
Second anniversary illustration of Lid.
Second anniversary illustration of Raegen.
Fan Festa artwork
Mombert and Hess' Four Sages.