Dead Space Enemy

Dr. Challus Mercer
A doctor aboard the USG Ishimura, a devout Unitologist and one of the main antagonists of Dead Space. In the wake of the calamity that has gripped the Ishimura, Mercer has become a religious fanatic, attempting to convince the crew of the Ishimura to commit mass suicide. Mercer often works to bar the progress of Isaac and even attempts to kill him outright, sending a "prototype" regenerating Necromorph nicknamed "Hunter" after Isaac several times throughout the course of the game. He may be responsible for getting rid of most the escape pods in the "Ishimura" in order for the crew to be killed and become Necromorphs, as he allows to happen to him. To Mercer, everything that has happened is God's will; he insists repeatedly that Isaac should die and allow their "children" to take over.

from wikipedia