It's all based on the Me'am Lo'ez on Parshat Noach.
The Patrusim & Kasluchim (also offspring of Mitzrayim from Cham) indulged in the immorality of exchanging wives. From these adulterous unions came the Plishtim (Philistines).
The Lehavim (also offspring of Mitzrayim from Cham) acquired this name because their faces were like flames (not sure if in shape or some other quality). Lahav is "flame" in Hebrew.
Kush, Mitzrayim, Put, and Canaan were the leaders of the plan to build the infamous Tower of Babel.
Chatzermavet (literally: "courtyard of death) was the grandson of Ever (via Yaktan), who descended from Shem.
A nation of ascetics descended from Chatzermavet. The Me'am Lo'ez states they went around unclothed "like the Dervishes" and "were interested only in death."
Only recently did I have a clue as to what this could possibly mean.
Could this be the ghoulish Aghori cult on the banks of the Ganges River in India?
(For more on them, please see: How Going to the Extremes of "Transcendent" Spirituality Leads to Disturbing Death Rituals & Cannibalism.)
This aligns with Rav Gedalia's theory in Shalshelet HaKabbalah that all the sons of Yaktan ended up in the East. While certainly there are countries even farther East than India, his specific term is that they ended up on the eastern "side," which easily includes India, as well as the Far East.