Dattatreya
"Shri Dattatreya was a dropout of an earlier age than the period when Veda and Tantra merged to become one simple cult. It was men like Dattatreya who helped to make this possible. Three of his close disciples were kings, one an Asura and the other two both belonging to the warrior caste. Dattatreya himself was regarded as an avatar of Maheshwara (Shiva) but later was claimed by Vaishnavites as the avatar of Vishnu. Not such a sectarian claim as it appears; Hindus regard Shiva and Vishnu as the same or as manifestations of the Absolute taking form."