Practically all of his attacks can be blocked. If you move close to him, he will use an attack that is incredibly easy to get a synchronized block on. Just block the moment you see him attacking and it will most likely be a synchronized block. Then, use the Direct Counterstrike combo while he is dazed and repeat the process. Once your attack is over, he will use the same strike as before, allowing you to block and attack almost indefinitely. This works for both the start of the battle and after you get your magic back. While this does take slightly longer than magic-infused attacks, this is useful if you are trying to finish the trial and want to prevent Pan from healing. Basically, just get close, attack and block.