Mr. X is not a traditional boss fight but a persistent threat throughout the RPD. He cannot be permanently defeated until the very end of the game. Your best strategy is to evade him. If you must fight, aim for his head to stun him temporarily, giving you time to escape. He is immune to most small arms fire. Save your powerful ammo for other enemies. Listen for his heavy footsteps to anticipate his arrival. Running is often the best course of action when he appears.
