After his transmutation by his mother, the Regess, Corg became a Prince of the Invid, with his siblings Sera and Ariel being Princesses. Unlike his sister Sera, Corg was overcome with emotions such as rage and anger. He demonstrated ruthless and sadistic traits in his defense of not only his mother but the Invid Hive.
During the Battle for Reflex Point, the Regess placed Corg in charge of defending Reflex Point and destroying all those that threatened it. He was elated to take these actions and prepared to leave only to be stopped by Ariel, who had returned to the Invid after spending time among the Robotech Rebels. She had grown fond of humanity and developed empathy for them, even falling in love with their leader Scott Bernard. She tried to convince him to stand down and cease this offensive, but he refused. He shoved her aside and left. Sera, on the other hand, agreed with Ariel and turned upon him.
He brutally assaulted the attacking Rebels, who were being bolstered by the returning Robotech Expeditionary Force, and inflicted heavy casualties. Midway through the battle, he detected human life signs inside Reflex Point itself, and interrupted peace talks between the Regess and the Rebels saying he would never stand down. Upon hearing this Scott became determined to stop him and engaged him in his Alpha Fighter, only to be was shot down by the Invid Prince. At the same time peace talks broke down between the two sides as the full might of the REF arrived to take back the planet. Bernard only survived the fight thanks to Ariel's intervention when he crashed. (New Generation: Dark Finale)
Corg continued to slaughter REF forces as the battle progressed, but a short time later Bernard returned in his Beta Fighter. Corg grew overconfident in his skills due to his first victory and soon he found himself outmatched. Defiant to the bitter end, he was killed by the rebel leader, and the Invid defenders of Reflex Point collapsed. Shortly afterwards, the Invid withdrew from Earth, and the Third Robotech War ended. (New Generation: Symphony of Light)
Behind the Scenes
The New Generation role playing game supplement by Palladium Books states that Corg's remains were never found within the wreckage of his Royal Command Battloid, and that he may have been able to teleport out of the mecha before it exploded. As with all non-narrative sources, this wiki has elided not to view this as legitimate.