Your battle with Ganondorf has some similarities with your encounter with Phantom Ganon in the Forest Temple. When he fires balls of magic in your direction, use the Master Sword to deflect them back at him. Keep doing this until you score a hit with one of the deflections. You will have a split second to aim and shoot a Light Arrow at him. As he falls to the ground stunned, Navi will briefly be able to help you. Target Ganondorf with the Longshot and pull yourself next to him. Strike with your Master Sword, then quickly target the stained glass in one of the corners of the room. You will be able to latch onto the stained glass and pull yourself to safety before Ganondorf slams the ground. Each time he slams the ground, more of the floor will fall below, leaving only the corners left to stand on. If you fall to the floor below, climb the middle structure and quickly target a corner with your Longshot. When you start to run low on supplies, check the breakable pots below. As Ganondorf gets weaker he will start to build up multiple shots. While he is doing this, you have an opportunity to stun him with a Light Arrow. Repeat the process of deflecting, shooting a Light Arrow, targeting him with the Longshot, striking with the Master Sword, and escaping to a corner until he is defeated.