Wikipedia
Heruka
Heruka is also a name for the deity of the Cakrasaṃvara Tantra.
Heruka (Sanskrit; ), is the name of a category of wrathful deities, enlightened beings in Vajrayana Buddhism that adopt a fierce countenance to benefit sentient beings. In East Asia, these are called Wisdom Kings.
Herukas represent the embodiment of indivisible bliss and emptiness. They appear as Iṣṭha-devatā or meditational deities for tantric sādhanā, usually placed in a mandala and often appearing in Yab-Yum.