Black Siren's powers and abilities
Meta-Human Physiology
After Laurel was struck by the energy of the S.T.A.R. Labs particle accelerator explosion on Earth-2, her DNA mutated and enhanced her vocal cords.
Superhuman Sonic Scream
Laurel is able to emit a sonic scream that comes from her voice, with the highest known frequency being 250 decibels. Laurel's scream is powerful enough to produce enough force to launch a full-grown human and other heavy objects back several feet. Her scream can also shatter a marble statue, steel arrows and kill a human being by causing internal hemorrhaging. With one shout, Laurel caused a tremor that took down all of Mercury Labs. She is well known for collapsing buildings with her powers on both Earth-1 and 2. Laurel is also immune to her own powers and can control the range of her screams, creating seismic waves large enough to collapse a building or small enough to enter through the ear, causing internal damage on a fatal scale even if the target has regenerative powers. She is even able to create a sonic bullet by blowing a kiss.
Abilities:
Peak Human Condition
Laurel is in top physical form and strong enough to swiftly incapacitate, hurl through the air, or even break the neck of a grown man and beat up much larger foes with relative ease. Laurel's reflexes are fast enough for her to react to an incoming arrow in order to shatter it with her powers. Her durability and resilience are remarkable as she was able to get up without any visible injuries after getting hit by Wally West's car, stand up after being knocked down by a shockwave from a sonic scream battle with Dinah Drake and survive being shot in the stomach. Her conditioning also lets her recover from most injuries very quickly, though not superhumanly. However, her suit may have materials that enable this to be possible. Laurel later demonstrated the ability to survive a close-range gunshot at the stomach while in civilian clothes.
Acrobatics/Free-Running
Since becoming Black Siren, Laurel has developed free-running skills and could drop from a height of several feet without injuring herself. Her skills allow her to fluidly dodge and attack from different directions without losing balance. Laurel was able to incapacitate Dinah by jumping on her and holding a knife to her throat in seconds. She was also able to perform a backflip without using her hands during a fight against Dinah.
Honed Senses
Laurel has sharp hearing and sight, as well as keen skills of perception. She is able to pick up incoming danger and react quickly.
High-Level Intellect/Expert Tactician/Leader
Laurel is an extremely intelligent and observant woman, able to determine at first sight that Cisco Ramon and Caitlin Snow were not their Earth-2 doppelgängers. Also, she is an accomplished leader and tactician, due to her former status as one of Zoom's top lieutenants and leading her own group of criminals. Laurel has also proven to be very effective in anticipating her enemies patterns of thinking and use it against them, purposely leaving a map of City Hall for Team Arrow to find making them believe that the Star City police ceremony was her target, while it was actually the Arrowcave.
Master Deceiver/Manipulator
Laurel is an exceptional liar, as once she was given all the information about her late Earth-1 counterpart, she was able to successfully portray herself as her doppelgänger to various people and even to the public. Laurel is also capable of befriending or seducing others in order to make them feel at ease with her before she kills them.
Multilingual
It was implied that Laurel speaks some level of Mandarin and Cantonese in addition to English.
Master Lawyer
Laurel is a very quick learner, having gained a great deal of knowledge of the legal system from her late Earth-1 counterpart's old schoolbooks and began using it to her advantage. After 5 months, Laurel's skills as a lawyer improved to the point that she became the new district attorney of Star City, although the public is still under the impression that she is her Earth-1 counterpart (thought to have been dead) who had previously been Star City's assistant district attorney. She is considered the best DA Star City has had in years.
Expert Investigator
Laurel's experiences as a lawyer also make her a capable investigator and she has exceptional instincts; she was able to deduce of Felicity's pregnancy just by looking at what she was eating.
Expert Interrogator/Torturer
As the district attorney, Laurel proved to be skilled in interrogating suspects. Laurel is also capable of torturing her opponents if the need arises.
Master Combatant/Martial Artist
Laurel is a highly proficient close combatant, while battling the Flash, she demonstrated a series of well-coordinated punches and kicks after disorientating him with a sonic scream. Laurel's combat skills are proven to be superior to Dinah Drake's, a highly skilled combatant in her own right, even overcoming her bare-handed while the latter was armed with her signature bo-staff. Laurel was also able to match and even push back Dinah whilst she was fueled by rage over Vincent Sobel's death, although not without considerably greater effort. She also defeated an entire group of FBI agents, albeit completely disarmed. Laurel is even skilled enough to hold her own against master fighters, like John Diggle and Silencer, a member of the Longbow Hunters, but she was ultimately defeated.
Expert Stick-Fighter
Laurel is an accomplished stick fighter, using Dinah's bo-staff to take down both her and Quentin Lance. She also effectively used a massive pipe to battle Honor, one of the Longbow Hunters, but was unable to best her.
Expert Markswoman
As a long-time criminal, Laurel is an expert in the use of many types of firearms. She was able to systematically take out a group of Diaz's men in a firefight.
Master Knife Wielder
Laurel managed to quickly incapacitate Dinah and hold her throat at knife-point in order to prevent her from using her powers, all while moving extremely fast. Laurel is also skilled in using knives in long-range combat; she was able to kill a man with a single stab by throwing a knife at him even though he was in her field of vision for only an instant.
Indomitable Will/High Tolerance for Pain/Expert Survivor
Laurel is a very resilient, driven, determined and nearly fearless individual. After being knocked down by an explosion caused by the confrontation between her and Dinah's sonic screams, she was able to get back on her feet within seconds. Laurel was even able to survive taking a bullet to the stomach and despite being knocked out, was able to get back on her feet upon awakening and fully recover in just five months, though her suit may have helped her.
Intimidation
Due to her incredible power and her well-known coldness, Laurel commands an intimidating presence, instilling fear into both enemies and allies.
Stealth/Infiltration
Laurel can quickly vanish from sight after disorienting her enemies with her sonic scream. She can just as easily catch her enemies off-guard without her powers.