- "People need to be afraid. Even if it means we have to sell it to them."
- —Mercy Graves[src]
Mercy Graves was a criminal, former Cadmus agent and Lex Luthor's former head of security at Luthor Corp. She is also the sister of the late Otis Graves and the former close friend of Lex. After Lex's arrest, Mercy and Otis went to work for his mother, Lillian Luthor, at Cadmus. Following Lillian's arrest and Cadmus' disbandment, Mercy and Otis helped Ben Loclkwood/Agent Liberty found the Children of Liberty, backed by an unknown entity.
Mercy and Otis were both later killed by a Hellgrammite as revenge for capturing and brainwashing the latter.
In 1996, Mercy Graves and her family went on a vacation to an unknown destination. During this time, Mercy somehow caused dangerous harm to her brother, Otis, to the point that paramedics were called in an attempt to resuscitate him.
Working at Luthor Corp
At some point, Mercy became acquainted of the Luthor family and began working as Lex Luthor's head of security at Luthor Corp. Their relationship grew over time and eventually, Mercy became Lex's closest friend and confidant. Mercy also grew close to Lex’s younger sister Lena, whom she took under her wing and became a big sister figure to. Mercy even personally taught Lena how to shoot a gun.
Mercy eventually grew frustrated with Lex’s hyper-focus on Superman instead of looking at the bigger picture. Feeling that intelligence wasn’t enough and humans needed to find a way to match the superhuman abilities aliens possessed, Mercy left Luthor Corp.
When Lex was arrested, Mercy turned states witness against him and provided evidence that helped put him in prison.
After Lex's incarceration, Mercy and her brother, Otis, began working for Lex's mother, Lillian Luthor, at Project Cadmus. However, Lillian was also later arrested by Supergirl which caused Cadmus to be shut down.
Working with Agent Liberty
After hearing of Ben Lockwood and his friends harassing and killing alien immigrants, Mercy met up with him and the two spoke in her car. She told him that whilst his work was good, it was sloppy as she was able to locate his fingerprints at the scene. She then gave him body armour and proposed that they work together to further get rid of aliens. She explained that their plan was to expose President Marsdin as an alien and introduced herself and Otis. She then showed him a file of a woman named Fiona Byrne who was their first alien target due to her being an alien rights activist. The three began to work together and Ben took on the name "Agent Liberty".
Under the orders of Liberty, the two ambused Dr. Rohan Vose outside his lab and proceeded to use lasers to slice off his spikes that stuck out of his arms in order to gain access to the lab. After Otis took one he took the other for playful reasons and Mercy criticised him for not acting professional. Just as the entrance to the lab opened, Supergirl smashed through a window but was deafened by a device used by Otis and had her legs handcuffed together by Mercy. Otis then shot her through a window at the end of the corridor and the two entered the lab. However, Supergirl managed to escape from the cuffs as Mercy found the package they were looking for. As the two prepared to leave, Supergirl flew back in but stayed behind in order to protect Dr. Vose from a bomb thrown down by Otis as the brother and sister made their escape. The two travelled back to Agent Liberty's lair and when Otis began playing with nunchucks, one of them hit something and Mercy threatened him not to do it again. When Liberty entered, Mercy told him their mission was successful but when Otis told him that Supergirl showed up she kicked him. Liberty then asked for the EMP and when shown it, he told then siblings to prepare for war.
Later, at President Marsdin's gathering for aliens, Mercy and Otis were instructed to attack it and after stealing uniforms from two D.E.O. agents, they threw the EMP which turned off all the lights in which the gathering was being hosted. Once inside, Mercy mudered an agent with a gun and attempted to kill Alex Danvers but was unlucky with every shot. She then threw down her gun and the two began fighting. Mercy quickly disarmed Alex and even managed to floor her, throwing a bomb once she was down and running away. The sibling then attempted to flee on motorcycles but were followed by Supergirl. Knowing she couldn't lose her, Mercy resorted to shooting Otis in the shoulder which caused him to fly of his vehicle and was sent plummeting down, forcing Supergirl to stop and rescue him. As she did so, Mercy managed to escape. Later, back at Liberty's lair, him and Mercy watched the news report of the reveal of President Marsdin being an alien. Liberty then complimented her on her work and she explained how much she loved her country. He then moved onto a woman he had taken hostage and killed her, explaining he was an agent of liberty.
While wearing a red wig in order to not be recognised, Mercy got into an elevator with a man who was carrying a laptop with him and when the doors closed, she strangled and killed him with her bag and took his laptop. She then returned to Agent Liberty, who was watching the news report about Supergirl stopping a riot outside the White House, and exclaimed that getting the laptop from the victim was easy. She then showed him that she obtained a vial of Kryptonite and explained that they wouldn't kill her and that it was just a security measure. Mercy later used the laptop in an attempt to permanently disable any image inducer that an alien in National City was using. However, Lena Luthor managed to use her computer in her office to put up a firewall and stop Mercy. Enraged, she destroyed the laptop.
Later, Mercy travelled to L-Corp in order to destroy the image inducer for good. She used super-sonic sound waves to incapacitate everyone in the lobby of the building, including the security team, and took over the whole building. She then spoke to Lena through one of the televisions and expressed her disappointment in her for allowing her to get in so easily. One Lena got into one of the elevators with Kara Danvers and Eve Teschmacher, Mercy spoke to her again and complimented her on the way she had laid out her company.
Whilst the three evaded Mercy's men, she snuck into Lena's lab and took one of the arms of the Lexosuit and came out of hiding when Lena and Kara entered the room. She asked Lena to join her because they had the same views, humans needed to focus on being as powerful as aliens. However, Lena quickly denied the offer and after attempting to talk her into it, she grabbed the other arm of the Lexosuit and shot at Mercy. She then got Kara to leave the room and her and Mercy began to fight. After failed attempts at shooting, Mercy got close to Lena and kicked her into a wall but she quickly got up and the two pointed the suit's guns at each other but before either could do anything, Supergirl showed up and pinned Mercy against a wall and managed to stop her. She was then incarcerated alongside her brother in the D.E.O.. Her and Otis' cells were later checked up on by Raymond Jensen and she attempted to convince him that the D.E.O. were the villains and that Earth didn't belong to aliens. This speech worked as Jensen later broke both Mercy and Otis out of their cells and returned to Agent Liberty's lair with them. Mercy then used a device previously used by Supergirl to defeat the Daxamites and filled it with Kryptonite, releasing Kryptonite into the air.
After they released the kryptonite, the three were greeted by Liberty, who unmasked himself in front of Jensen. Believing that Jensen had fufilled his purporse, Mercy grabbed him and held a knife to his throat, ready to slit it, however, she was stopped by Liberty, who convinced her that Jensen could get them into the D.E.O..
In stark contrast to her brother, who is playful with his crimes and work, Mercy is very cool, calm and collected as shown when torturing Rohan Vose. When Otis was lasering Vose's spikes off his arms, he laughed and exclaimed that he was having fun whilst Mercy criticised him for acting like a child. During her conversion with Agent Liberty. she displayed her patriotic side as well as her beliefs of human supremacy.
- Peak human physical condition: As a former head of security and Cadmus agent, Mercy is in top physical condition after having undergone extensive training.
- High-level intellect/Expert tactician: Mercy has shown that she is very intelligent and is capable of using a computer or laptop to hack anything, even being able to set up a whole security system in a company.
- Computer specialist/Expert computer hacker: After stealing a laptop from an employee at L-Corp, Mercy was capable of using it to hack into the mainframe and briefly disable any image inducer in National City that an alien was using. She was also able to design the entire security mainframe for Luthor Corp.
- Expert Combatant/Martial Artist: As a formal Head of Security of Luthor Corp, Mercy is an expert in unarmed combat and martial artist. Mercy has proven to be skillful enough to match up against Alex Danvers, a highly skilled combatant in her own right.
- Expert Markswoman: As a long time Head of Security, Mercy is an expert in firearms and was capable of shooting and killing an agent from an extended distance. She was also able to shoot her brother in the shoulder whilst they were both on motorcycles.
- Red wig: Mercy briefly used a red wig when attempting to stay undercover and when retrieving a laptop from an L-Corp employee.
Behind the scenes
- In DC Comics and and the cartoon series Superman: The Animated Series, Mercy Graves is the right-hand woman and assistant of Lex Luthor and aided him in most of his crimes. Unlike the cartoon series where she first appeared, the comics version was also an Amazon.