Dark influence cannot be handled by any living entity. Once it has infected a host, it will take control and pursue its will on the overworld. Demons have been banished for such a time that people are no longer warned of the dangers they can still pose and as such, when fel energies are detected, its already too late.

Golems are the only known entities that can not only handle the energy, but purge it from itself. Where that energy is sent to is unknown, but thought to be sent back to the demon lands.