The storyline of Enigma made a sense of relation to the sense that Christian is the heartless person everyone thinks he is, and even with a slight light of hope, he reverts to his old relationship patterns.
Sean's storyline also relied on showing peoples nature,with a stumble in his ethics and some would say standards in woman. It ends up saddening me in the conclusion.
All in all the Christian/Liz storyline was the most heartbreaking to watch, because of Christians obvious destruction in his relationships with woman, and his inability to be loved. Liz has obviously decided to cut the fat and move on with her life.