Another special case of slaves are fighting slaves. Since in this case you normally use male specimen it isn't viable to use sexual pleasure. It gives the slave a feeling of beeing dominant. It would be preferable to use stuff like food or other short time luxuries as a reward. Also males are significantly harder to break in these cases since if you want good battle slaves you need to use men with a minimum strength and willpower to make good fighters out of them. These attributes however make males prideful. The pride is a problem since it won't allow them to give up easily.
Also to train battle slaves it isn't a viable option to use drugs since most drugs have side effects which significantly lower the fighting power.
As you can see training fighting slaves is a hard project. Similar to the Masochists however the rule is: It won't always work but there is a will there is a way.
So let's reorganize the training from the scratch. Training a Battle Slave also needs dependency. So starting at a place far away were he only can escape into danger is still viable.
Battle slaves should go through strict training regiments from the beginning. During all that they should feel inferior. So in the best case you can establish a feeling of inferiority towards you. You shouldn't degrade them. If you degrade them they will feel hate towards you. Later during the fighting training that could lead to your death.
It is also important to know what they want to reach in live. Training a slave that way is not much different from being a employer.
Also the same rules as in slaves. Never break rules you set and never punish them without reason. It is still true that you have to be the constant in their lives. There existence has ro be bound to you. They need to feel goid while listening to you and bad if they break your rules. Battle Slaves take much more time to train since it is best to train them from childhood. It is hard to make people kill other people. The best way is to teach them morales according to what they shall do for you. Death shouldn't be a big thing for them from the beginning of their life. They need to learn to kill early.
Important is to teach them who ro kill and who not. The easiest is to make them feel thankful, indebted and guilty to you. These three things have to be very deep and refreshed regulary. So take care of your slaves. Indoctrinate your wishes into them. Tell them always the truth. They don't serve higher goals they serve you. Why? Because you raised them. Why shall they kill? because you want those people death. Is it worth risking their lifes? Yes . And why? Because you want it.
You have to teach them absolute loyality from the beginning. Never let one of them be bullied you risk the programm through singularities breaking out.
humilation isn't the right way. Only do that when they have done something that breaks the rules and deserves of that punishment.
Always make sure they feel valued equally and only give benefits as a reward. If one gets more benefits than the others for no apparent reason then you have a problem. Make a list of merits they can get and a list of things they can do. Never let a merit go on eternal. Everything is limited.
If you give out to much it isn't viable. You have to pay for the rewards. You cannot guve them out infinitely.