The kids couldn't even say something to him as Axel had already left to join back his daughter, and so Maya told them, "Do your best, fight like one, and protect each other."
Maya then got up, and the kids got ready. She then joined Peter, while Axel and Kevin went to place themselves around the arena to be able to intervene rapidly if something went wrong. Only then did Maya motion for Peter to start the countdown.
Willow could only use a small part of her powers, and she was sure that her Dad wanted to test her.
Those vines weren't powerful enough to harm her, and it was a friendly fight, so it was the perfect opportunity to check if she was able to use all the fighting techniques she had assimilated thanks to the knowledge she had obtained through her bloodline, and those that she had learned from them.
