Kālarātri aka Kālī along with Bhairāva serve as the seat of Cakrasamvara and Vajrayogini. So it is really quite impossible that Kālī can be Vajrayogini. In reality, Cakrasamvara and Vajrayogini emanated from Akaniṣṭha to counteract Bhairava and Kālī.
proof please, do you have the original Sanskrit/ tibetan scriptures - or is this simply your opinion?
When asked a Lama who resided in tibet, whist i was visiting Kailash, years ago. Who is Vajrayogini trampling on. 'Tell me more about this this bewitching dakini', i beseeched this Vajra master.
He replied, in very good english may i add: 'the doctrine of vajrayogini, is not for the uninitiated and followers of tainted, polluted western scholars - concentrate on good dharma, noble truths, and the triple gem - perfection of these simple measures will instil true knowledge, and arrest the lies of the false preachers growing greedy off the imprudents trapped in samsara’.
I was taken back, and somewhat confused. After talking to several Tibetans regarding the enigmatic practises of Vajrayogini, it was inferred her teaching by true lamas, who are impassive to the hoarding of westerners for personal profit, would expect total surrender of one’s identity; to relinquish material chattels, and live a selfless, monastic life of servitude for the good of others, as was prescribed by the Buddha to the Bodhisattvas over the aeons.
Back in Kathmandhu, I learnt that the two figures she was trampling on was Kalratri, and Bhairav.
Kalratri, was the seventh manifestation of the goddess Durga, rather than Goddess Kali per se.
Dictionary of Hindu Lore and Legend (ISBN 0-500-51088-1) by Anna Dhallapiccola
She is the fiercest form of Goddess Durga, she is synonymous with Bhairavi, and wields the thunderbolt (vajra)
Epithets for Vajrayogini: Krodikali (= angry kali) Krodhakali, Kālikā, Krodheśvarī (she who is agitated), Krishna Krodhini (krishna means black in sanskrit, krodhini = angry – hence angry dark one); Tibetan:Troma Nagmo:khros ma nag mo; English: 'the Wrathful Lady' or 'the Fierce Black One'
References: as a lot of people on here love wikipedia, i took the initiative to look-up the reference taken on wikipedia's Vajrayoginī page.
The Forms of Vajrayoginī Himalayan Art Resources http://www.himalayanart.org/image.cfm/490.html
Vajrayoginī - Krodha Kali (Wrathful Black Varahi) http://www.himalayanart.org/search/set.cfm?setID=359
Finally, not sure if Varahi and Cinnamunda have been ,mentioned, again these great yoginis and emanations of shakti revered by both shaktas and some vajra practitioners alike, although their are some noticeable differences on the methods of practise involved.