A powerful,original,modern creation of what could be understood as an underworld initiation in a Western context is Carolyn Hillyer's Oracle of Nights and its accompanying musical production Cave of Elders. It works through a visualization,accompanied by evocative poetic text, that correlates progression within a sequence of caves with female biology and female biological cycles.
Qlippoth and Magic, Goetic Spirits ('Lesser Key of Solomon', etc.) What these threads illustrate for me is a lack of any kind of underworld initiation within the west over a period of time (Unless it assumed a Christianised form) I think the dealings with the Infernal and Fallen angels are a way to retain this kind of knowledge. If the contested idea of kabbalah having a greek origin is taken into account and the greek notions of thought that influenced Judaic thinking are observed then perhaps it is natural within the context of modern thought and its development to create an underworld that seems to be lacking to the modern practitioner. A way of reclaiming hell in a sense or redefining it out of Judaeo Christian terms into modern and post modern Magickal and Neo Pagan narratives. People seem to approach this by re-appropriating Christian mythology with adversarial mythopoesis or turning to the envisioning of other traditional narratives of the After or Under.
The narrative structure of the Threshold has largely received an authoritarian narrative in western cultures because of perhaps the power their is perceived to be in controlling the definitions of such borders as those between life and death, punishment and pleasure for example. This restructuring or recapturing of these thresholds is perhaps why so many now enter into these so called 'darker' areas. As any kind of ancestral lineage is heavily established in Orthodox norms, some establishment of creative, rewarding and illuminating explorations are undertaken in order to regain a sense of connection to what feels to have been lost, yet remains an inherent part of life and the psyche.