Cyborg, the mighty machine man was earlier a part of the Teen Titans, but becomes a part of the Justice League due to change in the Flashpoint narrative.
When Flash goes back in time to save his mother, the entire structure of DC Universe changes. The world gets sets at a war, superheroes come become anti-hero, but Cyborg becomes a savior and hero. When the world goes back to normal, Victor Stone becomes a part of the Justice League.
Taking about powers, the mighty machine is equipped with great speed, strength, and agility. He can also fly with a rocket pack hung on his back. Due to his robotic capabilities, he can create weapons like knives, lasers, etc.,