From
http://forums.projectego.net/devalions-fable-faq-1566/
Q: How do I beat Jack of Blades?
A: The first time you fight Jack, he has two forms of attack. In the beginning he uses a sword to attack you, often sending out hurtful waves of energy. The easiest way to defeat him in this form is to cast Physical Shield, Slow Time, and then cast Berserk. Now, whenever you hit him, you will smash through his blocking sword (he blocks extremely well) and damage him for a good amount. Halfway through the fight, Jack will change attack patterns. Now, he will stay in the center of the room, but he flies, so the sword is useless. Take out your bow, and cast Slow Time and then cast Multi-Arrow. Jack has a couple of very, very damaging attacks in this form. He still sends out waves of energy, but they hurt more, and there are more of them. His second attack drains you of life. Fortunately, if you are armed with Skorm’s Bow, and use Multi-Arrow, all you need to do is hit him 2-3 times to kill him. When he sends out the waves of energy, stand in-between the spaces of the energy bolts, charge up, and let fly. Do this until he is beaten.
The second time you fight Jack, he has a few new tricks up his sleeves. In preparation, when you are outside the Bronze Gate, cast Physical Shield and Multi-Arrow, and then use a potion to get your mana back to full. Now enter the gate. You will enter a large room brimming with lava underneath you (the action gets hot from here on out…sorry, anyways….). Now, when you have control of your character, immediately cast Slow Time and run to the left, up the stairs, and then go midway down the descending stairs. Why, you ask? Good question. Jack has two moves that are completely nullified by this position. One, a diving flame attack, will go right behind you. This attack HURTS…as in, it can completely wipe out your mana if you have your Physical Shield up. Jack’s other attack is a ground stomp, which sends debris out in front of him. The debris will not go up the stairs, so it will not damage you. About midway through the fight, summoners and minions will start to spawn. These honestly aren’t very big threats. Laughably, Jack will do your work for you in getting rid of the summoners, as his flame breath will kill them if they are standing above the staircase you are on. Now, as Jack settles back down after a flight, charge up your bow and wait for a lock on. Fire, and then immediately charge again and fire. There is a certain amount of damage that you can do to him before he must fly around again. Repeat the bow-charge-fire routine two more times and he should die.
