Giving us a sense of the hero-villain dynamic, screenwriter Hodson told IGN that Gotham City gangster Sionis is a "narcissist" with grudges against each member of the Harley's team.
"Each of them has such a personal reason why they don't like him and why he doesn't like them," she said. "That natural kind of antagonism with each of them feels personal and grounded rather than feeling like, 'I'm going to blow up the world,' big Machiavellian-like mustache twirling. And that felt so right in this world."
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This all-female group isn't quite as famous as DC's Justice League, so let's take a quick look at its 22-year history and who these characters are.
Comic book origins
It began as a team-up between then-former Batgirl Barbara Gordon (aka Oracle) and Dinah Lance (aka Black Canary) in Black Canary/Oracle: Birds of Prey, a 1996 one-shot by writer Chuck Dixon and artist Gary Frank. The idea was conceived by Jordan B. Gorfinkel.
Barbara, the daughter of Gotham City Police Commissioner James Gordon, had been shot and paralyzed by the Joker in the iconic graphic novel Batman: The Killing Joke (from writer Alan Moore and artist Brian Bolland). But she took on the Oracle identity to provide intel and other technical backup to Batman and her other allies.
Black Canary is a martial artist with the power to emit a high-powered sonic scream known as a "canary cry."
In 2003, writer Gail Simone brought Helena Bertinelli (aka Huntress) into the team, giving the squad its most iconic trio. (A healed Barbara would later suit up as Batgirl again.) The team's most recent series, Batgirl and the Birds of Prey, wrapped up in May.
Cassandra Cain first appeared in 1999's Batman No. 567, having been created by writer Kelley Puckett and artist Damion Scott. She's the daughter of two assassins who became an agent of Oracle and later inherited the Batgirl identity. She took the name "Orphan" after the death of her father, who'd used it.
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Montoya was created by Bruce Timm, Paul Dini and Mitch Brian for Batman: The Animated Series and introduced to the comics in Batman No. 475 in 1992. She starts out as a detective from the Gotham City Police Department, later inheriting the role of the masked detective known as The Question. Since then, she's been returned to her original role in the GCPD, as the partner of Harvey Bullock.
Black Mask, the movie's bad guy, was created in 1985 by writer Doug Moench and artist Tom Mandrake for his debut in Batman No. 386 and is among the Dark Knight's most unpleasant villains. The masked crime boss, whose real name is Roman Sionis, is among Gotham's most powerful, and he just loves to torture people.
The movie won't be this team's first live-action appearance, but it's highly likely you missed its short-lived TV show. It was set in a Gotham City that was abandoned by Batman, forcing the trio to protect it in his place.
The show's main villain was Harley Quinn (played by Mia Sara of Ferris Bueller's Day Off), who poses as Helena's psychiatrist and tries to discover her secrets as she works to avenge an incarcerated Joker.
This was originally published on Sept. 25, 2018, and has been updated as we learn more.
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