what are master moralities and slave moralities?
Master morality self-creates values (what is good for me is good) in affirmation of life and power. Also recognition of the inequality of people - some are just more ambitious, capable, intelligent, etc.
The weak resent/envy/hate the strong (master morality), since they'd like to be strong and accomplished, but are too afraid or incapable. Out of revenge (their morality is reactive not creative), they turn morality on its head. Good = obedient, weak, poor, ugly. It's Jewish/Christian values.
Nietzsche's crit is that Judaism and Christianity are not religions of love, but hatred. They hate (from envy/resentment) the independent, strong, egoist. And they hold the best of us down with fictions like equality, a judgy God, etc.