Context: One of the antagonists comes into the room and they talk with one of the other characters for a while. As the antagonist turns around and is about to leave, one of the other characters takes out their sword and tries to attack her. She uses her magic to reflect the attack and they are sent flying across the room and then she responds with:
Is she saying that if he was going to try and attack her, he should have done it at the start or does this mean something else?
Edit: If it is of any help here is a link to a video which contains the scene. The scene is from the 10:20 point to 10:50. This video contains spoilers for the game ルフランの地下迷宮と魔女ノ旅団.