Deathstroke was first introduced in the comics in 1980 in New Teen Titans No. 2. Born with the name Slade Wilson, Deathstroke is an expert assassin with super strength and stamina. He's often been part of Green Arrow's rogues' gallery, and on TV has been played by Manu Bennett on CW's Arrow.

There's already been plenty of speculation as to whom Affleck's Dark Knight will face off against, with Suicide Squad introducing chief antagonist the Joker (Jared Leto) into the DC Extended Universe.

Affleck, whose Batman first appeared in March's Batman v. Superman: Dawn of Justice, also appeared in this summer's Suicide Squad. The actor is currently shooting Warner Bros.' Justice League in London, with Zack Snyder's superhero teamup film set for Nov. 17, 2017.

No date has been set for Affleck's solo film. He also will direct and star in the adaptation of Agatha Christie's short story Witness for the Prosecution for 20th Century Fox.