Deathstroke (real name Slade Wilson) is a member of the Light. Originally the group's enforcer because of Sportsmaster's departure, he has since risen through the ranks and became the leader of the League of Shadows.
Much like his predecessor Sportsmaster, Deathstroke is cool and efficient in the discharge of his duties. This emotionless mask does tend to slip when he is truly challenged, and a degree of impatience slips through. This is evident when he was engaging with Sportsmaster, while Tigress bantered with Cheshire. He also takes great delight in the thrill of battle, and takes a sadistic relish in taunting his opponents.
Unlike Sportsmaster, Deathstroke is far more ambitious, as he made plans to "take a seat at the table" at the head of the Light.
Deathstroke is a tall, slender man, with long white hair, and a full beard. He is missing his right eye, and wears an eyepatch, while the remaining eye is blue. His armor is primarily black and gray, with goldenrod greaves and gauntlets. He wears a matching goldenrod mask with a black area that obscures the right half of his face, including his missing eye. He wears a utility belt with pouches, and sheaths for a sword and staff on his back.
By 2018, Deathstroke has cut his hair much shorter. He also changed his armor considerably, with much more orange in its color scheme. The suit has goldenrod shoulder pads and matching greaves and gauntlets. His mask now is made of cloth and includes two long ribands jutting from the back, one black and one orange, matching the colors of the front side of the mask.
When Sportsmaster attempted to assassinate Black Manta, Deathstroke counteracted the attack by shooting the disc Sportsmaster threw. This prompted Sportsmaster to blow his way out of the cave, and make his escape by helicopter. Deathstroke fired several shots at the helicopter, but it escaped unharmed.
As Miss Martian and Lagoon Boy exited a Zeta-Tube in a junkyard, they were confronted by Deathstroke and Tigress. Deathstroke battled Lagoon Boy, eventually taking him down and injuring his leg. Tigress was then able to weaken Miss Martian long enough for Deathstroke to slap an inhibitor collar on her. The two then took Miss Martian aboard the Manta-Flyer.
Later, as Black Manta ordered Miss Martian to restore Kaldur's mind, Deathstroke observed in a ship a distance away from the Manta-Flyer to ensure that Miss Martian did not use her telepathic powers for any other reason.
Deathstroke continued to monitor Miss Martian's progress in restoring Kaldur's memories. He told Black Manta that progress was slow, not knowing that Kaldur was playing possum and that he and Tigress were trying to figure out how to save Miss Martian's life. Tigress informed Deathstroke she needed a break and Deathstroke excused her. Soon after Tigress left, Cheshire dropped into the room through a ventilation shaft, took down a Manta Trooper who had subbed for Tigress, and attacked Kaldur. Miss Martian intervened, but Deathstroke activated her collar to shut off her mental telepathy and alerted Manta about Cheshire's presence. He observed Miss Martian trying to protect Kaldur and then notified Tigress of the situation. As Cheshire and Miss Martian fought over a laser blaster, they took out Deathstroke's camera.
Deathstroke later boarded the Manta-Sub and caught Cheshire and Sportsmaster attempting to escape. He and Sportsmaster engaged each other, with Cheshire moving in to defend her father. Tigress intervened and took down Cheshire. As Sportsmaster and Deathstroke tussled, Sportsmaster mentioned how the Light betrayed him and could do the same to Deathstroke, but Deathstroke said that wouldn't happen if he took a seat at the Light's table. The battling duos were interrupted as Miss Martian arrived, who slammed Deathstroke and Tigress into the wall, allowing Sportsmaster and Cheshire to leave the sub. Miss Martian advanced on Deathstroke, who dropped explosive pellets on the ground that knocked Miss Martian away and released her telekinetic hold on him and Tigress. Deathstroke then charged Miss Martian, who telekinetically threw him into Tigress, allowing her to phase out of the sub.
In the comics, Slade Wilson is known as Deathstroke the Terminator, the world's most expensive assassin. He was originally a villain of the Teen Titans, and played a large role in the Judas Contract storyline. In the early nineties, he got his own ongoing series, which painted him even more in the light of a tragic anti-villain, burdened with guilt over the harm done to those near him.
This is his third animated appearance. He was a main antagonist in the Teen Titans animated series (where, for censorship reasons, he was referred to as "Slade"), and his alternate universe analogue was President of the United States in the direct-to-video film, Justice League: Crisis on Two Earths.