Michael Korvac is a human from the planet Earth who was abducted by the Kree who infused him with unstable cosmic powers which drove him power-mad and insane. Until his encounter W.A.R.R.I.O.R. who helped him realize his mistakes and help him return to normal.
The Avengers: Earth's Mightiest Heroes
Michael Korvac was a normal human, until while driving through a mountain area when he was taken by the Kree, and experimented with him for a long time, which gave Korvac incredible destructive powers, which he used to destroy the Kree ship and escape. However, the experiment had costed Korvac of his insanity in which he then used his power in destroying a space-station, an inhabited planet, etc. in which he enjoys it, before returning to Earth.
He landed in Central Park, creating a crater, claiming to being pursued by aliens. The police take him to the Avengers. After Wasp brought his wife, Carina Walters, to the Avengers Mansion to be with him, the Guardians of the Galaxy appeared in search of Korvac. The Avengers battled them as Michael escaped along Wasp and Carina. When the Guardians explained the Avengers the threat Korvac represented to the universe, his powers manifested and he knocked out everyone in the scene but Carina, and escaped with her and a unconscious Ms. Marvel who he knocked out in battle.
He arrived to Central Park and continued to battle Ms. Marvel under the reason to protect Carina. When the Avengers and the Guardians arrived, he fought them until Carina made him note he was scaring her and that he became a monster. Out of remorse, Korvac then teleported himself to the deep of space, possibly to another dimension, for parts unknown.
He would later re encounter the Avengers when he returns to Earth to find Corrina and make it up to her. But when he did he not only encountered the Avengers but their new allies W.A.R.R.I.O.R..