Vajradhara...if I m not mistaken, in Vajrayana, is the tantric form assumed by Sakyamuni Buddha right?
And in the Sarma Traditions (Gelug, Kagyu and Sakya), He is the Dharmakaya & Tantric form of Sakyamuni Buddha, who is the Adi/Primordial One, the essence of Sakyamuni's perfect enlightenment (Samyak Sambodhi), the combined of the Tenfold Directions' Buddhas and Three periods of Time...so I read...
In Nyingma Tradition, He is Samantabhadra, who again is the Primordial Buddha, representing the complete realization....
Not sure if wiki is correct...
Heruka (Tib.khrag 'thung) or "blood drinker", is the name of a category of wrathful deities, enlightened beings in Vajrayana Buddhism that adopt a fierce countenance to benefit sentient beings. Herukas represent the embodiment of indivisible bliss and emptiness. They appear as yidam or meditational deities in tantric sadhana, usually placed in a mandala and often accompanied by a yab-yum consort.
The name "Heruka" is made up of the prefix "he-" meaning "hey!" and "ruka", a rich term implying many levels of subtle meaning - richness, royalty, etc are implied by "ruka". It is linked to the Sanskrit word "Rc" which is where the name "Rgveda" comes from. The famous bodhisattva of the second chapter of the Mahayanasutra "Sovereign King of Golden Splendour" (suvarnabhasottamendraraja) is called "Ruciraketu" - "He Who Flys the Banner of Riches (ruchira)" - is a lay emanation of a Heruka
Eight Herukas of the Nyingma Mahayoga
The eight Herukas (Wylie: sgrub pa bka’ brgyad) of the Nyingma mahayoga tradition (and their corresponding sadhanas) are said to have been received by Padmakara from the Eight Vidyadharas (Tib. Rigdzin), or Eight Great Acharyas: Manjushrimitra, Nagarjuna, Vajrahumkara, Vimalamitra, Prabhahasti, Dhanasamskrita, Shintamgarbha and Guhyachandra. They were proficient in the practices of, respectively,
1) Yamantaka (Tib. Jampal Shinje, ’jam dpal sku) the wrathful Manjushri, the deity of body
2) Hayagriva (Tib. Pema Sung, padma gsung) the wrathful Avalokiteshvara, the deity of speech
3) Vishuddha/Sri Samyak (Tib. Yangdak Thuk, Wylie: yang dag thugs) the wrathful Vajrapani deity of mind
4) Vajramrita (Tib. Dudtsi Yonten, bdud rtsi yon tan) the wrathful Samantabhadra, the deity of enlightened qualities
5) Vajrakilaya/Vajrakumara (Tib. Dorje Phurba, phur ba ‘phrin las), the wrathful Nivaranavishkambin, the deity of action
6) Matarah (Tib. Mamo Botong, ma mo rbod gtong) the wrathful Akasagarbha, the deity of calling and dispatching
7) Lokastotrapuja-natha (Tib. Jigten Chotod, ’jig rten mchod bstod) the wrathful Ksitigarbha, the deity of worldly offering and praise
8) Vajramantrabhiru (Tib. Mopa Dragnak, mod pa drag sngags) the wrathful Maitreya, the deity of wrathful mantras