only the shaman possesses the power of the psychopomp. For one thing, because he has traveled it many times himself, he is thoroughly familiar with the road to the underworld; then too, only he can capture the intangible soul and carry it to its new dwelling place.
Eliade establishes the psychopomp function as the shaman's exclusive competence, grounded in his repeated personal traversal of the underworld road and his unique capacity to handle disembodied souls.
, Shamanism: Archaic Techniques of Ecstasy, 1951thesis