Emotionless (3.5e Trait)
From D&D Wiki
Emotion has run dry on you, you simply lack any.
Benefit: You gain a +2 bonus to saving throws made against compulsions.
Drawback: You can never benefit from morale bonuses.
Roleplaying Ideas: You may have still have a bit of emotion but not much, maybe some for a lost love or a loving mother... who knows.