4. Mirror Marlena Moreau
Mirror Marlena Moreau starts as the archetypal “captain’s woman,” but quickly becomes the episode’s wild card and its clearest example of how someone in the Empire can still be swayed by decency. As Kirk’s confidante, she knows about the Tantalus field, the secret weapon in his quarters that lets him erase enemies from existence with the tap of a control panel.
Marlena's decision to use that weapon to save Kirk from Sulu’s assassination attempt shows both how complicit she’s been in Kirk’s reign and how quickly she recognizes the possibility of something better when she realizes this James T. Kirk is different.
By the time Kirk is encouraging Mirror Spock to seek her out as an ally, Marlena has quietly shifted from accessory to tyranny to potential partner in reform, hinting that even in the Mirror Universe, loyalty can be redirected toward a nobler cause.