There's nothing illuminating about how they handle Yeager/Buffie, and the latter's self-destructive attraction. I'm glad we find it baffling, it's good that it's outside our emotional world, but it reminds me of something in The Sopranos, where they did attempt to explain it. Tony, the mob boss, falls for another patient of his psychiatrist's, whom he meets in the waiting room. The woman starts mood-shifting, alternating being nice and seemingly provoking him, to puit it mildly, for no apparent reason. The psychiatrist lets Tony know (getting around the confidentiality thing somehow) that self-disrespect can be expressed by someone going out of her/his way to provoke a very violent person (like a mob boss or Mr. Hyde), to get the punishment he/she assumes she/he "deserves", underneath.
Buffie doesn't provoke Yaeger, but she doesn't have the fiery temperament for that, and besides, Yaeger doesn't wait to be provoked! Anyway, the psychiatrist equated it to the "suicide by cop" phenomenon. Who in her right mind would go out of her way to associate with Yaeger, unless she somehow expected his kind of treatment, and in some way was seeking it out?
