when you're wandering around in refinery, you noticed a Helghast soldier doing push the button open the lift. Then, a Helghast Heavy Trooper named Arc Trooper appeared with his electricity gun. He shot his electricity gun, then prepared to fight with you and said in deep menacing robotic voice

Get ready for this shock! I'm Arc Trooper! This strongest Helghast heavy soldier enemy is ready to defeat you! Hahahahaha!