As Demons feel very little in terms of physical pain it is often seemingly impossible to torture one. However for a trained hunter this is not the case. In hunting there will be frequent situations in which a hunter will be required to gain information from a demon, or wishes to cause one harm out of revenge or retaliation. Similarly a trained torturer of hell will have expertise in causing their fellow demons to suffer.
The key with torture is to combine a demon's weaknesses. In the case of what is avaliable in the Cathedral this will be Iron and Holy Water. However supplies of some of these are limited and so human hunters need to be cautious of what they use.
Wounds
Iron blades/ bullets can be used to inflict physical wounds on a demon. This will cause them to actually feel the pain inflicted upon them, and even though they will recover from this it may hurt them or at least cause them to momentarily faulter. However it is important to keep in mind if the body the Demon has possessed belongs to a loved one that if the wound inflicted is fatal then it will certainly kill the human possessed once the demon is exorcised.
Holy Water
A weapon like a blade can be dipped in Holy Water to maximise the pain a demon feels. They can also be forced to drink holy water, in which the burning sensation a demon feels on their skin when they come in contact with holy water will be also felt on the inside. The benefit to this is whilst holy water hurts the demon, it does no damage to the human body and therefore the human inside may still be safe once the demon has been exorcised.
Obviously torture is mostly about creativity. Highly trained torturers in Hell have all sorts of devices to cause pain to the human souls that arrive in Hell, as well as techniques to maximise pain and suffering. Naturally in Hell a human soul recovers from their damage instantly so torture can happen again and again, but that does not mean that they cannot prolong each session. Humans in the cathedral will need to be able to adapt to this sort of attitude if they want to successfully break a demon- their bodies can heal quickly so pain will have to be continuous to gain any information.
