Titans has found its Mercy Graves, casting Natalie Gumede to play her in season 2. This comes on the heels of Iain Glen's casting as Bruce Wayne, not to mention the addition of Deathstroke's family, which makes for quite a busy second season.
Mercy Graves originally appeared in a 1996 episode of Superman: The Animated Series, called "A Little Piece of Home." She was then incorporated into the comics, starting as an Amazonian bodyguard to President Lex Luthor in Detective Comics #735. She's since been part of nearly every possible DC medium, including the recent Supergirl season and live-action films like Batman V. Superman, but always in connection with Lex.
It looks like the Luthors will still be a big part of her story, according to the character bio Deadline reported. The Titans producers describe Mercy Graves as "the ruthless, cunning, right hand and bodyguard to the notorious Lex Luthor – serving her boss with unquestioned loyalty. Her connection to the Luthors runs deep, as Mercy has been a friend of the family and in Lex’s life since they were young." It'll be interesting to see how that family history plays into the show, seeing as Lex hasn't been cast, at least not yet.
As for Natalie Gumede, her biggest claim to fame is the role of Ashley Carter in the 2014 Doctor Who Christmas Special, but it's far from her most prestigious credit. She also starred in ITV's Jekyll & Hyde miniseries, where her character Bella ruled the criminal underground of London and romanced Hyde himself. Her other credits include supporting roles in Free Reign and Rig 45, not to mention two years on the long-running British soap opera Coronation Street. Last but not least, she was a contestant on Strictly Come Dancing, a popular competition series akin to Dancing With The Stars.
Gumede will join Titans as a recurring guest star this season, which opens plenty of storytelling possibilities. It's not yet clear what connection Mercy will have to the existing Titans characters, but there's at least one newcomer she's guaranteed to cross paths with: Superboy. Conner Kent is a clone of Superman - or close to one, at least - and wherever Superman goes, Lex Luthor follows. Perhaps Graves' episodes in season 2 will pave the way for her boss to make his entrance later on, as part of an overarching plot.
Titans still needs to wrap up the Trigon arc before starting its Slade Wilson saga, not to mention introduce Superboy to the team, which doesn't leave much room for other characters. Additionally, Curran Walters was upgraded to series regular on the strength of his performance as Jason Todd. With the team expanding, there's a chance they'll bring their own villains with them - and Mercy is the perfect adversary for Conner, hinting at his origins without taking over the season.