Father Coulmier was the in-house priest for the Special Containment Center, a top secret super-criminal prison facility located several miles underwater. While he appeared to be nothing more than a mild-mannered man of the cloth, he was in fact a member of a sect that revered Norman Osborn and his alternate persona, the Green Goblin, with religious fervor, believing him to be so evil and anti-establishment as to be the Antichrist and the bringer of a "better world".
When Osborn was transferred to his facility from the Raft, Coulmier and several inmates orchestrated a prison riot to cover his escape. As a "test of faith", Osborn asked Coulmier to overload the pressure gauges of the facility after he and a few others left in an escape pod in order to cover their tracks. Coulmier did as he was told, and perished in an explosion along with every remaining prisoner still in the structure.
Though supposedly an ordained priest, Coulmier has stated that he is not an actual Catholic. Despite this, he still regularly quotes Scripture.