While Scott was distracting the giant by buzzing around its head in that constant manner, Barda was busy coming up on the creature from the front, although as it spun around she would find herself facing the back of it. She was watching him move carefully, though she'd seen him fight before. It was easy to see that he relied on speed rather than strength, though it did not surprise her given the fact that he was much smaller than so many of their kind. Small and one would think weaker though she knew different, having watched him escape time and time again.
Barda swung the mega rod at the back of the giant's knee, hitting it right at the weakest point and driving the creature to it's knees with a single, brutal blow.
It was not the only strike she'd attempt on the monster, as she'd already be moving to hit it again. Perhaps someone else might have asked why they were attempting to destroy it - but Barda only knew that it was attacking her. So, it was entirely logical for her to do the same in return.