The 'BC Extras' (BCエクストラズ, Biggu Shiti Ekusutrazu) is one of Nation-A's official LBX tournaments and cosplaying contest. It is an anime-original event that appears in the Danball Senki anime filling between the events of Brinton and Camberlin in the game's timeline.
- All participants are to attend in tag teams.
- All participants must wear their own costumes
- LBX Customization and change of costume is admitted anytime during the tournament.
- Costumes weared during battle are graded by audience reception. Automatic disqualification will occur if the audience grades the cosplay as bad.
- Galactic Hero Senshiman Team
- Revenge Army of Hell Team
- Earth Defense Team
- Twilight Dragon Knights Team
- Team O.T.A.
- Team Double Rose
- Stealthy Alpha Team
- Magical Sister Brothers