The lineage Gurus of the special Highest Yoga Tantra practice of Heruka body mandala, and the Deities visualized during this practice.  

For a detailed explanation of this practice see the book Essence of Vajrayana, and the sadhanas Condensed Essence of Vajrayana, Essence of Vajrayana, Vajra Hero Yoga and Union of No More Learning, and the CDs Songs of the Heroes and Songs of the Vajra Father.