When you are on fight pit arena you can fight the beast underground by locking on, running backwards and doing a back roll through the fence, then go up the elevator and use the control switch to drop the center of the pit, go back down the elevator and run to the other side of the arena away from the beast so it falls down the hole, touch the fence so that it kills you, push continue and you will start back in the arena, fall down the hole and then jump on the beast if its head is in the wall, it will hurt you but will free the best from the wall, you can now fight the beast in the basement.