The tenebre-bok love the carosen. Protecting them is their life and their highest calling. They do not talk often, but they aren't stupid. They are, in fact, quite eloquent, if one can persuade them to speak, or, as proves easier, write.
Shetthis Nor wrote, "We know the kenaki made us this way. The khibakrhi are lying, cheating, cruel beasts, but the kenaki made them that way. We know the kenaki made the carosen to hide the cruelty, but the carosen are innocent of that. We and them, we are kindred, souls trapped in bondage on this dying earth, and by whatever gods hear our words, we will let nothing happen to our charges. This world would crush them if we weren't here. They don't even realize the world is as horrible as it is, and if all we can do is to help maintain that illusion, then we will."
Carosen mean more to them than even their own children. Tenebre-boks are asexual, and, once reaching the age of four, lay several eggs every year. They give the eggs to the carosen to raise. A tenebre-bok is given a carosen to protect from the moment of birth onward.
With luck, a tenebre-bok will not ever lose its charge. The kenaki made them to only live as long as the carosen they've bonded with. This is a biological self-destruction, triggered by the grief of the loss, and it's possible to override it with drugs or magic, but most tenebre-bok choose to pass on such treatment.
They are not free-willed creatures, but in their artificially imposed purpose, they seem to find a sort of freedom. Many tenebre-bok endeavor to consciously extend their protectiveness and fairness to all, regardless of their imperative to only protect carosen. Some tenebre-bok take it upon themselves to create all manner of beautiful art, to entertain their charges, and perhaps to foster some hope in the others. Some tenebre-bok go mad.
Artificially imposed drives, it would seem, can decay. Rogue tenebre-bok are rare. When they do occur, it's usually because their carosen has been killed, but not always. Rogue tenebre-bok are usually harmless, and want to be left on their own, but some actively hunt the very creatures they were made to protect. This frightens the carosen beyond words, and so the other tenebre-bok do not speak of this to them. They simply kill any rogues they find.
Tenebre-bok are ten foot tall, bipedal insects. They have simplistic, armored faces, without much in the way of expression - just two tiny eyes peering out from a flat, blue-gray mask. They have a bony, jagged red crest atop their heads, and, like the carosen and khibakrhi, have two fingers and a thumb, and two toes. They have no tails. Most tenebre-bok shroud themselves in huge cloaks, stitched together from shaggy jench hides or fasmat leather.