I forgot, what's the MC's main motivation? Or is he just an asshole for no real reason?
It seems like he has a grudge against the gods
Having just binged the series, the gist is that the gods treat humanity as disposable playthings to pit against one another in gladiatorial combat for their (the gods') amusement, a group of seven people rose up and tried to kill the gods, but were betrayed and defeated.
The MC is implied to be one of those seven, which explains his grudge against the gods, why he can't use magic (previous chapters said they were cursed to
only be able to use "new magic", but it's presumably a mistranslation and it's actually the reverse), and would mean his motivation is largely to keep the truly exceptional people from becoming pawns of the gods, even if it means turning them into his sex slaves.
Or, at least, that's my read on things so far.