Although they don't directly interact, the fact that Ninian can be summoned means she gets a chance to meet with her potential future son Roy.One of Adult Tiki's castle idle lines is her expressing gratitude on how she's finally able to see her old friends again including her beloved "Mar-Mar!" In addition, one of her lines when her profile is tapped has her ask if "Mar-Mar" is here.
Even some villains, like Zephiel or Michalis, actually show respect instead of overly belittling you (though they do warn that you better not do something to lose their respect). This may consist of promises to protect you, as your weapon is useless in a straight fight, or vows of friendship.