Mercy Graves is a secondary antagonist in the DC universe, first appearing in No Man's Land comic. She is mainly featured as the bodyguard and partner-in-crime of Lex Luthor, and assist her boss in his battle against opposal foes. She is a secondary player in the Non-Disney vs. DC Villains War.
Non-Disney Vs DC Villains War
After Zartan's imposture is revealed, Luthor calls upon Mercy to capture Zartan, while the mercenary attempts to escape. They eventually corner him and interrogate him for more information, he would reveal. They, then, put Zartan into the cells of Belle Reeve. Mercy Graves makes a brief appearance, when Luthor sends Derek Powers, an associate of his, into a chemotherapeutic station, in order to heal his wounds, from his severly radiation, caused in the aftermath of the battle between Powers and the Crimson Twins.