Yangdak Heruka
Yangdak Heruka (Wyl. yang dag heruka) or Vishuddha (Skt. Viśuddhaheruka) is one of the eight deities of Kagyé. The wrathful manifestation of Vajrasattva, he is similar to the deity known as Chakrasamvara (Tib. Demchok), who is practised in the Gelug tradition. It is said that all the deities of the Mother Tantras are included in the practice of Yangdak.
In the Longchen Nyingtik, the Yangdak practice related to Palchen Düpa is called "Union Of The Buddhas" (yang dag sangs rgyas mnyam sbyor).