The inhabitants of Cheron were an extremely long-lived race; one representative of them was reputed to have pursued another such representative, an accused criminal from among his people, across the Milky Way Galaxy for over 50,000 years. Unfortunately, the species destroyed itself in a civil war caused by racism. There were only two known survivors by 2268, who the crew of the USS Enterprise believed would ultimately kill each other due to their hate.
Cheron natives possessed extremely fast space ships with an advanced cloaking technology, and also possessed advanced protective shielding systems on their persons, which could also be utilized to disrupt sensitive computer systems and as weapons against others. Some members of the species could also command advanced technological systems by sheer willpower alone, bringing vessels as large as a starship entirely under their control to send where they pleased.
Physiology and culture
Inhabitants of this planet bore a peculiar physical appearance: their skin was exactly half-black and half-white, with some white on the right side and black on the left, and others the opposite. The one Cheronian sub-species had acquired supremacy over the other sub-species, but exactly how this had happened was never explained, and it could be, and indeed was, assumed that even the two surviving specimens themselves did not know.
Those who were "black on the right side" considered those "white on the right side" to be inferior, and had organized a "Commission on Political Traitors" as an agency of the government of which they had acquired control. They subjugated their brethren in what they thought was a gesture of mercy and compassion, but the "whites on the right side" considered it nothing but slavery and oppression. By 2268, civil war had completely destroyed their civilization, leaving only two known survivors, Bele, "Chief Officer Of The Commission On Political Traitors," and Lokai, an accused criminal whom "Commissioner" Bele had been pursuing since circa 47,730 B.C.E. at the latest, and probably long before even then.
Bele referred to Lokai as "half-white" in a tone clearly meant to disparage; Lokai referred to Bele as "half-black" in a similar fashion. These references were obviously pejorative in both their cases. Both talked primarily in what amounted to clichés about (in Lokai's case) racial equality and/or (in Bele's case) the inherent supremacy/superiority and/or "rightful" subordination/inferiority of any one race over, or to, any other, and there was no real dialogue between the two.
However, from Bele's negative reaction to Kirk's suggestion that his people were once of one color, and both aliens' hostile, contemptuous usages of derogatory phrases such as "monocolored trash" and "monotones," it may be assumed that they both regarded their own dual-colored life forms as being superior to any and all singly-colored life forms. (TOS: "Let That Be Your Last Battlefield")
The novel No Time Like the Past describes the Enterprise briefly returning to Cheron, with scans revealing that Bele and Lokai have now set up bases for themselves on different sides of the planet; a time-displaced Seven of Nine notes that, even in her era, the Federation avoids Cheron due to the unpredictable power and life-span of the surviving natives. The novel also reveals that the Cheronians were finally destroyed permanently when an attempt by Bele's side to create a virus that would destroy only their enemies resulted, instead, in the virus being released before it was ready during an enemy assault, with the result being that both sides were destroyed. (However, Kirk and Seven, temporarily trapped in the past, were unaffected by the virus.)