Bonus XP/blood quality for discovering a citizen's secrets creates an unusual dynamic.

[Illudium]

From a purely mechanical standpoint, it seems as though you only get real benefits from getting to know a given citizen better if you then go ahead and feed on them. That's fair enough, but it does create an odd segregation between the mechanics and the story.

It seems as though a pacifistic "tortured monster" who fights the urge to feed on humans at all times has no real incentive to establish a personal connection to anyone, and might just as well keep his distance from people most of the time. Meanwhile, a "horrible demon" who views the humans as nothing more than a food source has to care deeply about the people around them, learning everything there is to know and going out of their way to heal the sick so they can maximize blood quality. It's an interesting change of pace from the traditional "sympathetic compassionate hero, apathetic villain" dynamic

[yugiinving]

learning hints will give you extra xp, which is nice.
Also Healing citizen will give you xp. but yeah I expected extra side-quests for thoses who decided to resist the blood tempatation. but there is nothing.
hoverer, since I have yet to fight Doris and I am already lv 30, I don't have a single reason to even feed on NPC.