Not really, the slave part with rewards and fan service is actually the least interesting thing in this manga. The fights and powers and monsters and whatever are more interesting. Fan service at this point is pretty much only good for silly faces and skipping through to the actual good stuff.
Anybody wanna hedge their bets on the reward ending and her continuing? Cause, I mean, if the rewards are just his true desires and it is just a kiss, I'm def leaning towards our boy falling in vanilla love