I thought you were looking for a manga where MIND CONTROL saves girl from slavery... I was like... aren't most of those stories about how someone USES mind control to force some girl into slavery? ... hahaha
Shuna no tabi-the first one that springs to mind Suits no kuni-i think, havent read it in a while +Anima sort of has it, but when the mc saves the girl from slavery they turn out to be a boy XD i cant remember if he saves anyone else, its a long manga....but has a similar main character and ambient to magi. Vinland saga-umm this might happen in this, its sort of in the process and i think they will save her but its ongoing so I cant say for sure. Put it this way, mc tries to save a girl from slavery.