Sayid and Shannon's relationship is brief but transformative for both. Shannon stops performing helplessness; Sayid opens himself to love after Nadia. Shannon's death at Ana Lucia's hands shatters Sayid and sends him down a dark path that defines his arc for the rest of the series. In the flash-sideways, Shannon is Sayid's constant -- not Nadia. The show argues that the Island's love was the real one.