What is Dual Brave Burst Progression? gumi Support Team - July 25, 2019 08:19 The progression system allows Summoners to increase the effectiveness of their Bonded DBB Unit's skills. Have more questions? Submit a request Comments Related articles [Unit Detail] Which units are DBB-eligible? How do I activate BBB/BSBB? How do I increase a Bond Level? What does the Progression System actually improve? What is Bonded Brave Burst(BBB) and Bonded Super Brave Burst (BSBB)?