Deathstroke (Arrowverse)

Slade Wilson a.k.a. Deathstroke is an Australian Intelligence agent and a recurring character in the Arrow TV series. While he initially was depicted as an anti-hero in Season 1, he later became a full antagonist in Season 2. He is played by Manu Bennet.

Biography
When Oliver Queen was marooned on a desert island, he was accosted by a group of guerillas, led by a man wearing a black and orange mask. He's recused soon enough by Slade, who offers to train him so that they can stop the guerillas and get home. Slade reveals that the masked man who caught Oliver was his partner Billy Wintergreen. Wintergreen had gone rouge and betrayed Slade, hence his hiding. Whne Oliver and Slade stop the guerillas, they gain an ally named Shado.



In the second season, Slade was fatally injured by an explosion that burned half of his face. Later, he was physically enhanced by a serum named "The Mirakuru" that healed his injuries and gave him super-speed and super strength but at the cost of his sanity. He then heads to Starling City and partners with Sebastian Blood and creates the Blood Cult. Slade knows his former friend Oliver Queen's secret identity as the Arrow and vows to destroy everyone he has ever loved. Then Slade will put an arrow through Oliver's eye. He then kidnaps Oliver's sister Thea and tells her that Malcolm Merlyn is her real father, leaving Thea devastated. Slade frees a bus full of prisoners and offers them a proposal to join him. He and Isabel Rochev then kidnap Roy Harper and transfer his Mirakuru-infected blood to the prisoners. Oliver and John Diggle arrive and rescue Roy, leaving Isabel mortally wounded. Slade then transfers his blood to Isabel, healing her wounds.

Trivia

 * This version of Slade Wilson is similar to Ra's al Ghul from Batman Begins. 
 * Both trained the protagonist
 * Both hold grudges against said protagonist
 * Both appeared separated from their traditional appearances. Ra's al Ghul had a decoy while Slade had a partner.
 * Both are allied with a masked villain who is a prominent part of the community whilst experimenting with dangerous toxins. Scarecrow for Ra's al Ghul and Brother Blood for Slade.