Cut The Cheese
Alright, attacking through the bars is a pretty cheesy combat technique. The Knight 'acts defensively' and Scooby-doos you. He goes to one side of the cage so you can't hit him. Then you walk around to his side to get to him, and he goes to the other side. Then he goes flush against the door and starts sawing through the floor. This cage is designed to hold chained prisoners made of meat, not metal men with power tools.