34 years ago - Mercy Graves is born in Metropolis' Suicide Slums.
25 years ago - 9-year-old Mercy starts kickboxing to protect herself.
21 years ago - 13-year-old Mercy becomes a member of a Metropolis Street Gang.
14 years ago - 20-year-old Mercy is caught stealing from Lex Luthor. Having beaten Lex's bodyguards, he doesn't turn her in, but rather cleans her up and makes her his valet & bodyguard.
6 years ago - 28-year-old Mercy loses her arm and is placed in an induced coma when she is caught in the explosion Lex Luthor staged to fake his own death.
4 years ago - 30-year-old Mercy is brought out of her coma when Lex Luthor stages his return, given a weaponized cybornetic arm. She follows Lex to the White House.
2 years ago - 32-year-old Mercy is forced to turn on Lex Luthor when he falls from office in order to secure Lexcorp.
Mercy Graves is Lex Luthor's loyal valet and bodyguard, and it's heavily implied she might be quite a bit more. There's no illusion of romance in their relationship, that doesn't really seem like something Lex would be interested in. Instead, it just seems to be a matter-of-fact element of her employment. There's a lot about Lex's personality that can be interpreted from his relationship with Mercy, but of course, she debuted on an animated series that was ausensibly for children, so we're left merely to speculate.
Mercy's Comic History
Mercy Graves first appeared in the animated Superman series, made by the same creators who did the classic Batman series, where they created Harley Quinn. Mercy was clearly designed to give Lex his own version of Harley: she was sexy but also a formindable opponent.
Mercy transitioned into the comics fairly easily, but without a lot of fanfaire. She was a cool addition to Lex Luthor's story, but never really got much traction as a standalone character, because she doesn't have a ton of personality. At least compared to Harley.
Our Mercy Story
In the comics, Mercy is actually one of a pair of bodyguards, Mercy & Hope. There's a lot of fun intrigue to be gleaned from Lex's singular relationship with Mercy, so we decided to keep her as his lone valet. Also, when Mercy was shown in the animated Young Justice series, she had a weaponized cybornetic arm, so we did the same thing. She's often depicted as being more than just a bodyguard, but also doing some of Lex's dirty-work out in the world, and we really like the idea of her slowly becoming more and more of Lex's personal black-ops agent.
Mercy's Costume & Future.
Mercy's animated series costume is pretty uniform, but there might be a reason why she never really took off like Harley Did, becuase is wasn't exactly interesting.
While her comic book looks have been a bit more deliberately sexified, it's kind of hard to ignore that they're also just generally cooler. She has a penchant for miniskirts and cool matrix-style jackets. Perhaps if anything, this can be a transition that she makes over time as her role as Lex's valet & bodyguard expands, becoming his confidant and acomplice. She gets a cybornetic arm weapon, and more autonomy within Lex's organization, almost becoming his proxy.