this appears to be Matrceta (also called Durdharsakala), who according to some is Ashvagosha, (rta dbyangs), and in Dic. comes under Lobpon Pawo. Ashvagosha is one of the Four Shining Suns of India (with Nagarjuna, Deva and Kumaralabha), though not, it seems, one of the Six Ornaments. (Check tape. DKR does say rgyan drug). [ZT, 2006, translator's notes]