Keep blocking and sidestepping his attacks while finding open spots for attack until you get about one quarter of his life down. After that, he will run off and enter a room will large heaters and mist around them. When Faustus jumps on to a heater, proceed towards the start of the mist trail that leads to the heater and pull the switch to hurt him. Keep repeating this procedure until he jumps up on to a chain, then run to a corner of the room and stay there until Faustus jumps down . He will now try jumping and kicking you from far away. If you sidestep his attack, he will hit the wall and will be vulnerable for a few seconds. Keep repeating this until he is dead.