NOTE: This article is about the incarnation of Deathstroke from the DC Extended Universe. The mainstream version can be found here: Deathstroke (DC).
You said you had something I'd want? You better not be wasting my time.
~ Deathstroke to Lex Luthor.
Slade Wilson, known as Deathstroke, is a minor antagonist in the 2017 superhero film Justice League, and a minor character in its 2021 director's cut, Zack Snyder's Justice League. He is teased to be a major antagonist in the future movies of the DC Extended Universe. He is one of Batman's dangerous enemies.
Deathstroke is the DCEU's adaptation of the DC supervillain of the same name. He is a highly skilled and expertly trained mercenary, exceptionally skilled in both swordfighting and marksmanship. His skill in combat leads to Slade being recruited by Lex Luthor to form a League in order to best combat the threat the newly founded Justice League is posing to his criminal operations.
Not much is known about Slade Wilson's past, but he would become a mercenary and assassin under the moniker "Deathstroke". During his time as a mercenary, he would become a great enemy of the vigilante Batman.
After Lex Luthor has escaped from Arkham Asylum, he meets with Deathstroke onboard a super yacht. Arriving at the yacht in a smaller speedboat, Deathstroke is welcomed by Luthor who sarcastically claims that he was just celebrating Superman's return. Luthor claims that Superman and several other heroes seem to be founding some kind of League and Deathstroke interrupts him, threatening that Luthor better not waste his time. Luthor replies that he has too much to live for. As Deathstroke removes his mask, Luthor states that it is time that supervillains like the two of them get a league of their own - seemingly successfully recruiting Deathstroke for his own "Injustice League".
In the "Knightmare" timeline, Darkseid succeeded in collecting the Anti-Life Equation and managed to make Superman become one of his assets. Seeing that humanity was in peril, Deathstroke joined the Insurgency, which was led by Batman, to oppose the Regime and save humanity from Darkseid.
Powers and Abilities
Marksmanship: Deathstroke is a proficient marksman, and is skilled with many firearms.
Swordsmanship: He is a capable swordsman.
Master Martial Artist: Deathstroke is a noted martial artist, being highly skilled in most forms of hand-to-hand combat.
Deathstroke in Zack Snyder's Justice League, as of a member of the Insurgency in the Knightmare future.
In August 2016, Ben Affleck tweeted a video in which Deathstroke could be seen in full attire, causing people to believe that he would be a major villain in the DCEU's upcoming Batman solo movie. However, whether Deathstroke will be still appearing in the film it's currently unknown, as Affleck has retired from the role and Robert Pattison has been cast as Batman, changing the film's story into a detective one.
Ron Perlman, Stephen Lang and Arnold Schwarzenegger were all considered for the role of Deathstroke before Manganiello was cast.
Deathstroke was considered to become one of the two secondary antagonists of Justice League, alongside Lex Luthor, where they team up with Steppenwolf to kill the Justice League.
Joe Manganiello was previously considered for the role of Superman in Man of Steel.
Prior to the movie's release, there were rumors that Deathstroke's and Luthor's appearances had been cut from the movie. It was also debated whether Joe Manganiello would still play the role. With Deathstroke's appearance in Justice League and his implied return as a member of the Injustice League, this rumors seem to have been laid to rest.
Because of his role, the Slade Wilson in the Arrowverse will be absent indefinitely and his story arc for season 6 of Arrow involving his sons Joe and Grant will be discontinued.