In the Mansion Infiltration mission, there will be a room you must go through that is full of guard wires. In the middle of the room is a sword. If you take the sword and keep it for the rest of the mission, you will be able to bring it to any of the other missions. On the last mission, bring it with you. Use the left bumper to dodge his attack and let him fall over. Before he gets up rapidly press R . This will only require one or two times. Take your time in shooting him. Concentrate on dodging while he is shooting energy balls or throwing pillars at you. Bring a weapon with a silencer so that you can shoot him while he is trying to heal himself with people so he will drop them. Silenced weapons have the best aim -- you will only need to shoot once.