Black Widow

Natasha Romanoff, better known as the Black Widow, is one of S.H.I.E.L.D.'s best agents.

Powers and Abilities.
Natasha Romanova possesses no superhuman powers, but was presumably given the Red Room's variation of the Super Soldier Serum. Thus, she possesses peak human strength, speed, durability, reflexes, agility, stamina, longevity, and intelligence. These capabilities make her on level with other peak humans like Captain America.

Aside from her physical capabilities, Natasha is an incredibly well trained S.H.I.E.L.D. agent, possessing incredible hand-to-hand skills and espionage training. She is also an incredibly skilled liar and infiltratror.

Equipment.
Black Widow has wrist blasters that serve as range weapons and gadgets.
 * Wrist Blasters: Black Widow used those blasters attached in her wrist to attack foes and use them for stun kills or grappling hooks.