The Kusunda or Ban Raja (“people of the forest”), known to themselves as the Mihaq or Myahq (< *Myahak), are a tribe of former hunter-gatherers of the forests of western Nepal, who are now intermarried with neighboring peoples and settled in villages.
The Kusunda are followers of animism, though Hindu overtones may be seen in their religious rituals. According to the 2001 Nepal census, there are a total of 164 ethnic Kusunda of whom 160 were Hindus and 4 were Buddhists. The Nepali word Kusunda originally meant “savage”, as the neighboring Chepang and other groups traditionally thought of them as savages, but the Kusunda do not mind the term when speaking Nepali.
Their language, which is almost extinct, is an isolate:
Watters (2005) published a mid-sized grammatical description of the language, plus vocabulary, which shows that Kusunda is indeed a language isolate, not just genealogically but also lexically, grammatically, and phonologically distinct from its neighbors. It appears that Kusunda is a remnant of the languages spoken in northern India prior to the influx of Tibeto-Burman- and Indo-Iranian-speaking peoples.
An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia has a genetic analysis of the Kusunda buried deep within it.
Like the Munda the Kusunda seem to be an undiluted ANI-ASI population which admixed with East Asians. Being in Nepal I am not surprised that the Kusunda are far more East Asian than the Munda. No wonder people assumed their language was Tibeto-Burman in origin. But observe that like the Munda when ADMIXTURE fractionates South Asian ancestry into Northwest-Southeast components they entirely lack the Northwest element.