Prometheus

"Prometheus" is a mysterious hooded figure in Star City, bearing a dark uniform similar to that of the Green Arrow. Prometheus is evidently aware of Oliver Queen's secret identities as The Hood/The Arrow as well as The Green Arrow, evidenced by the fact he targetted victims whose names formed anagrams for people on The List.

Biography
Little is known of this individual's past, even his real name. At some point for reasons unclear, this individual became embittered towards Green Arrow and began acting as "Prometheus", wearing a dark uniform almost identical to his, but with a full face mask and additional weapons.

When Lieutenant Conahan was leaving the SCPD precinct, he noticed Prometheus on the rooftop. Mistaking him for Green Arrow, Conahan asked if he could help him, but was shot by an arrow. Conahan painfully tried to shoot back, but Prometheus dodged his shots, leaped to the ground and threw a shuriken to disarm him. As Conahan tried to flee, Prometheus threw a knife into his leg, knocking the cop down. As Conahan desperately tried to crawl away, Prometheus slowly walked up to him, sword in hand, and, when asked if he was Green Arrow, coldly replied that he wasn't, killing Conahan.

A few nights later, Prometheus somehow learned of Green Arrow's encounter with Tobias Church amidst his illegal deal with AmerTek Industries where he almost killed Green Arrow. In response, Prometheus stalked Church and as he left Club XLR8, he killed his two bodyguards. While Church mistook him for Green Arrow, Prometheus threw an ax into Church's shoulder, leaped to the ground and slammed Church to the pavement. Prometheus warned Church that Green Arrow was his to kill and if he killed Green Arrow then he'd die, too.

After a couple of weeks, Prometheus learned that Church had ignored his warnings and confronted him at the docks, reminding him of his threat and tried to kill him, but Church had his own bodyguard to protect him. Prometheus reminded Church he had his second warning and wouldn't be given a third and left. After Church was arrested following his defeat by the Green Arrow, being transferred to Iron Heights, Prometheus attacked the convoy of police cars escorting him. After slaughtering the escorting officers, he confronted Church in the police van. Church tried to plead for his life by telling him Green Arrow's identity: Oliver Queen. When Church asked if they were cool, Prometheus threw a shuriken into his neck and killed him, then left the scene of his slaughter.

Personality
Little is known of this individual though he appears to have an obsession on Green Arrow for reasons unclear. His fixation runs deep enough that only he wants to kill Green Arrow so much that if anyone else tries, he'll kill them as he threatened Tobias Church with death if he killed Green Arrow, and later kept his promise when Tobias refused to stop pursuing the Green Arrow. He is also ruthless as he mercilessly attacked an officer multiple times and slaughtered him in cold blood.

Abilities

 * Expert hand to hand combatant: Prometheus has shown expertise in armed and unarmed combat as he was able to nearly effortlessly defeat Evelyn Sharp in single combat, however she was able to tag him during their encounter.
 * Expert knife-thrower/Marksman: Prometheus is an expert in throwing weapons like shuriken, knives and axes. He managed to throw a blade to disarm a police officer.
 * Freerunning/Acrobatics: Prometheus is able to move and scale down walls with great dexterity and grace, even while throwing his shurikens and battle axe.
 * Intimidation: Prometheus possesses an intimidating presence. This can be due to his ruthlessness combined with his superior skill and mysterious appearance. Tobias Church showed clear signs of fear when the first pinned him against the floor and threatened to kill him.
 * Peak of human physical condition: As a highly-skilled assassin, Prometheus is in top physical condition. He managed to easily restrain the physically imposing Tobias Church with one hand and pin him to the ground after throwing a battle axe into the man's back.
 * Skilled archer: Prometheus has shown an expertise in archery managing to fire two non-lethal shots at a victim.
 * Skilled swordsman: Prometheus carries a katana and has used it to kill a police officer.

Equipment

 * Battle axe: Prometheus used a battle axe to injure Church.
 * Customized Recurve Bow: Prometheus carries a recurve bow.
 * Prometheus suit: This suit looks similar to the ones worn by Green Arrow and the Dark Archer, while the mask resembles that of Ragman. It is unknown what materials it's made from.
 * Shuriken: Prometheus used a throwing star to disarm Conahan and kill Tobias Church. He used similar stars in subsequent murders. It's revealed the stars are made from the arrows Oliver used when he went on patrol as the Hood/Arrow.
 * Katana: Prometheus used a katana to kill Conahan.

Behind the scenes

 * In DC Comics, Prometheus is an alias used by multiple villains. Although Marc Guggenheim stated that the show version of the character is not based on any comic character, he resembles the one depicted by Grant Morrison in looks and modus operandi, being a "dark mirror version" of the hero he opposes.