I've attempted several times, it seems the mission keeps score for you to check.The boss Black Magga is scoring a point for EVERY card he discards not just allies, the score tracker often reads 12 points heros, 40+ black magga, also I'm not sure the boss is supposed to swipe 3-5 cards per turn. Either the fight is incredibly unbalanced or its as I expect and bugged. Android galaxy 6s, normal difficulty, 4 hero group.