Board Thread:Questions and Answers/@comment-24113700-20150823013011/@comment-26297531-20150823022628

Ans 1: Every similar buff or debuff from BB/SBBs cannot stack with each other. UBBs used to be unable to stack with BB/SBBs, but now it's counted as a separate class of buff/debuff since the overdrive update, so it can stack with BB/SBBs now. Thus the DoT aka attack at turn's end debuff on enemies will override each other leaving the last to be applied in effect.

Ans 2: Elements buffs of the same type cannot stack. But using a mix of different elements allows you to get buffs from the different elements. For example, Quaid's 4 elements can coexist alongside Rinon's light/dark element buff.