Board Thread:Questions and Answers/@comment-24460299-20150206025141/@comment-3149389-20150206032151

LB = Limit Break. the new Limit Break System, is when you fuse a card with another copy of itself OR a Da Liu Ren card.

DLR = Da Liu Ren (tspecial cards used for limit breaking)

MLB = Maximum Limit Break, when you reach the limit (a card can be broken up to 4 times)

more info here