if they make the slavery totally permanent slavers will be free to get way more awful to the people they enslave. It could go to the levels of chattel slavery like the Americas did, where they make the children of the enslaved people enslaved from birth, instead of having to do it to criminals or prisoners of war. they would end up systematically erase the unpopular sentient enemies' freedom with a way more efficient method.
things will definitely go to hell.
Filia was sold into slavery by her mother, she’s not a POW, they already have chattel slavery.
You seem to be under the impression that the people in the old world didn’t practice chattel slavery in the same way they did in America, but this is false. a Roman slave owner could rape, beat or starve their slaves and would own their children too. There were some forms of debt slavery or contractual slavery where the slaves had some rights, but most slaves were literally property, often people kidnapped by pirates or the children of slaves.
I suspect that the narrative that American slavery was totally different and worse than the kinds of slavery you saw in the old world is leftist historical revisionism to try and make black people look more deserving of reparations and sympathy by making what happened to them a special kind of evil different from what happened to slaves in the Middle East or Europe and not par for the course in history. If it wasn’t then the conversation about reparations gets messy, then would the Turks have to pay reparations to their Balkan and Caucasian former subjects whom they enslaved? Would the Poles have to pay reparations to their Belorussian and Ukrainian former subjects? It gets really messy.
Serfdom and slavery are generally not the same thing, a lord does not literally own his serfs. A lord couldn’t legally sell his serfs or kill them on a whim. He probably could actually, murder used to be extremely easy to get away with and common, but it wasn’t legal. Serfdom in Eastern Europe however bore more resemblance to slavery. Serfs in Poland Lithuania or Russia could legally be raped, killed, conscripted into the military for life. Generally it was better to be a slave in America than a serf in Poland Lithuania since America has such an abundance of food that even slaves could expect to eat better than people in places like Ireland or Belarus.
Holy shit am I ranting too much, I could go on about the economics of slave importation in Brazil, the reason why despite importing far more Africans the Middle East doesn’t have large black populations like America, Korean slavery and a bunch of other stuff, but I’ll get back to the world of Halo and friends.
Slavery in their fantasy world has probably gotten as prolific as it will. The discovery of a new resource which requires a lot of hard labor or the discovery of a population genetically distinct from the humans in this world would be far more likely to profligate slavery. It seems that only the most dangerous monsters cannot be kept as slaves, so it would really just be succubi who would become available for ownership.