Entering into the Darkness

Seras is sweet and cute like any anime girl but she is totally different, she isn't like the annoying cute girls as the main protagonists love interest because she takes action a lot, is learning fast and she has a deep struggle she is overcoming thanks to Alucard and Integra.

And she rejects human blood at first because she doesn't want to hurt people in order to get it, she starts off with a bag of medical blood and now she is just trying to find balance where she can retain her humanity and compassion without going blood lust crazy like Alucard, she wants to get blood without hurting anyone and not kill anyone to get it, and she rejects Alucard's blood because she wants to be by his side for all eternity.