>>76803
That's basically all it does. It lets you customize the servants a bit by adding or removing perks. For example if you think "rape" or "execution" is annoying and want it removed, make your servant a "magic doll". Light green stuff on top is added. Dark green stuff on bottom is removed. The choice appears to apply to all servants, even if they die and you buy a new one.

Mercenary will also add "rape", although it doesn't say that it will.

Also, if you want to buy a new servant, know that the training center for each zone has different servants available. I didn't realize that for a long time.