Dame had been waiting for this moment, for the group to face the Light Faction with everything they had without the help of the items around them. It made the situation quite clear; if they had never had the Dark Magus items to begin with, they would have already lost this fight.
However, the main reason why Dame had come up with this strategy, or more rightly, Fixteen had, was because of the homing effect the gauntlets had. In order to use them, Dame needed to land a perfect hit on his target first.
Although the two of them were the same Pagna warrior rank, Beatrix was just far too skillful for him to land a hit normally. Even with the external Qi punches, it would be difficult for him to achieve.