Father Coulmier was the in-house priest for the Special Containment Center (S.C.C.), 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 the Green Goblin Cult, a sect that revered Norman Osborn with religious fervor, believing him to be so evil and anti-establishment as to be the anti-christ 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", Norman 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 died in an explosion along with every remaining prisoner still in the structure.