On Lucifer, Lucifer Morningstar makes an effective pseudo-detective thanks to his ability to get people to divulge their deepest desires, but during season 5, Lucifer loses the power he treasures most. Before meeting Detective Chloe Decker, Lucifer enjoyed squandering his gifts, using them entirely for personal gain and to maintain his hedonistic lifestyle. But after crossing paths with Chloe, Lucifer found a way to put his skills to good use. At first, his interest in police work was a way to amuse himself and an excuse to pursue Chloe, who was impervious to his "mojo" but over time, he became invested in the job. He could, after all, punish those deserving of his wrath before they wound up in Hell.
Lucifer utilized his mojo to get suspects to confess their innermost desires. When those secrets came to light, they uncovered motives pointing the police to the real killer or revealed information about the victims themselves. Lucifer wasn't able to charm his way into Chloe's mind, but he did charm her and after four seasons of will they or won't they, which equally frustrated and titillated viewers, the pair acted on their shared physical chemistry. And then afterward, season 5's "Our Mojo" introduced a new twist to their love story: Chloe could use Lucifer's mojo against him.
Chloe's newfound power had Lucifer questioning if he'd been passing on his mojo to all of his sexual partners like some celestial STD but it turned out to be a Chloe-specific loophole. His insecurities about becoming dispensible as Chloe's partner evolved into full-blow panic once he realized that he wasn't just sharing his mojo with Chloe, he had lost it altogether. Lucifer's lost mojo became a metaphor for him relinquishing control: He wound up in Hell because of a father-son power struggle of Biblical proportions, so this mojo FOMO presented a big hurdle for the rebellious King of Hell. It also introduced the problems Chloe and Lucifer are bound to face as the Devil navigates the complexities of a serious, committed relationship for the first time. The fact that Chloe's mojo only worked on Lucifer made her believe it was a sign he was opening up to her while, naturally, Lucifer was visibly shaken at the prospect that he had dropped his guard.
The series established angels have more control over their powers than they realize. Lucifer became physically vulnerable to Chloe because he wanted to, so the same could be said of his mojo. On the season 5 finale, "Spoiler Alert," Lucifer was frantic after Chloe's kidnapping. He regained his mojo just as Amenadiel was able to recover his ability to slow time during Lucifer season 2 when an injured Dr. Linda Martin's life hung in the balance. Both happened in the nick of time and clearly, Lucifer needed every resource at his disposal to find Chloe, so his power seemingly spontaneously returned. Fundamentally, it could be that the temporary loss of Lucifer's mojo was just a manifestation of his lingering doubts that he didn't deserve Chloe or it could be that Lucifer's mojo was no longer required when he was with Chloe, almost as if his individually tailored power left because a relationship made him more human.
The comings and goings of Lucifer's powers foreshadow problems for Chloe and Lucifer. God and Michael work in mysterious ways, after all. They've both used Chloe as a way to manipulate the former favorite son, and what God gives, he can take away, including his children's unique gifts. Fans will have to wait until the second half of season 5 of Lucifer to find out for certain God's plan (or Michael's) for Lucifer and what part his now vulnerable mojo plays in it.