Padmasambhava

"Flower Nectar: The Essence of Honey" (chos 'byung me tog snying po sbrang rtsi'i bcud)
Statue of Guru Rinpoche, Central Tibet, Tsang Valley, 15th-16th century.
Guru Senge Dradrog, a wrathful manifestation of Padmasambhava. (Painting in Tashichho Dzong)

The eight manifestations are also seen as Padmasambhava's biography that spans 1500 years. As Khenchen Palden Sherab Rinpoche states,

In accord, Rigpa Shedra also states the eight principal forms were assumed by Guru Rinpoche at different points in his life. Padmasambhava's eight manifestations, or forms (Tib. Guru Tsen Gye), represent different aspects of his being as needed, such as wrathful or peaceful for example.

Yang gsang rig 'dzin youngs rdzogs kyi blama guru mtshan brgyad bye brag du sgrub pa ye shes bdud rtsi'i sbrang char zhe bya ba

I am sustained by perplexity; and I am here to destroy lust, anger and sloth.

According to the great tertön Jamyang Khyentse Wangpo, the basic meaning of the mantra is:

hūm । oḍiyāne vāyavye । padmakesarakāṇḍe । siddhirlabdhātyadbhutā । khyāta padmasambhava । bahuḍākībhirāvṛta । tavaivānusarāmi । āyāhyadhiṣṭhānārtham । guru padma siddhi hūm ॥

Padmasambhāva had five main female tantric consorts, beginning in India before his time in Tibet and then in Tibet as well. When seen from an outer, or perhaps even historical or mythological perspective, these five women from across South Asia were known as the Five Consorts. That the women come from very different geographic regions is understood as a mandala, a support for Padmasambhāva in spreading the dharma throughout the region.

While there are very few sources on the lives of Kalasiddhi, Sakya Devi, and Tashi Kyedren, there are extant biographies of both Yeshe Tsogyal and Mandarava that have been translated into English and other western languages.