Tenakth
Legends say the Tenakth are cannibal reavers, divided into three clans constantly at war with each other. They managed to push back the Carja invaders during the Red Raids, and are known to have made their own incursions during the reign of the ninth Sun-King, Ranan. They are believed to be the controlling faction in the Forbidden West, though that knowledge is so old as to be highly suspect.
Tenakth can occasionally be seen in the Carja Sundom, recognizable by the heavy blue and white paint covering their shaved heads, accompanied by the blood-red paint around their mouths and down their throats.
The Tenakth homeland has not been named in Horizon canon.
Culture
Tenakth ascribe to a might-makes-right kratocratic ethos — something is earned by taking it, making the victor stronger and the loser weaker. This plays out in the constant warfare between their clans, where each is always trying to prove their superiority by taking from the others.
Tenakth in Skyline
Skyline takes the position that not all Tenakth are brainless brutes trying to kill each other all the time, but it’s easier for the Tenakth to let everyone think that’s the case. While many Tenakth may find the constant challenge and opportunity invigorating, not all would. Some would just want to be good at whatever they do, without having to fight for every inch. This might play out as the Tenakth leaving the clans to find a less hostile life, or maybe as the Tenakth creating or joining a collective who find safety in numbers.
While it does not seem the Tenakth are as industrious as the Oseram, or as connected to the machines as the Banuk, it should not be assumed they are unintelligent. The Forbidden West is a large area — holding it, especially against generations of invaders, would require solid tactics, strategy, and resource management.