Pneumatic vessels

All creatures in the material world hold pneumatic energy, small tidbits of creation energy left over from the original words of creation. Some humanoids hold more specific pneumatic energy. Tieflings, Aasimars, Etherborn and genasi all hold more pointed energy that attracts entities that search for such powers. Tiefling blood has the ability to withstand the devil and demon effects that normal humanoid bodies mgiht not. This makes tieflings major targets for demonic entities, both for possesion and rituals. The same is true for Aasimars though these are more attractive to celestial beings. Etherborn being quite special in this sense as they are open sources of pure creation power.