This is one of them. Conrad is a proffessional exorcist - not exactly something you brag about at parties, but it's a living - who has a personal grudge against one of the "horsemen" (High level demons that are crucial to summoning the Great Demon King).

He suffers from a demonic disease that is slowly eating him up from the inside, causing violent and extremely painful cramps every now and then - though he is in almost constant pain. The spots on his chest are indications of the progression of the disease: When they reach his face he will slowly start to rot alive. To counter this as much as he can he smokes certain cigarettes that can easily be classified as narcotic. but what the hey, when you're going to die anyway...