Upon discovery of his mutant powers, Charles Little Sky fled his Native American reservation, and found work on Ellis Island. The Puma (Thomas Fireheart) was sent to retrieve him by the tribe and got into a confrontation between Little Sky and the Avengers. This resulted in Little Sky using his powers and opening a warp from which the U-Foes, banished into the dimension known as the Crossroads, emerged. As the Puma and the Avengers battled and apprehended the U-Foes, Little Sky escaped through a dimensional warp he had created.

Later, after Little Sky adopted the identity of Portal, he went through a warp that returned him to New York City where he battled Darkhawk and was taken into custody by police officers wearing Guardsman Armor. They took his weapons and armor and held him under protective custody at a New York hospital until he was rescued by Darkhawk, Daredevil (Matt Murdock), and Captain America (Steve Rogers) from the U-Foes who were intent on acquiring Portal for their own purposes. Portal then revealed to Darkhawk that he had confiscated parts of his armor from an oponent resembling Darkhawk (actually a Mahari alien named Kistur). Portal subsequently escaped through a dimensional warp. A few weeks later he retrieved his armor and weapons from a research center, battling several men wearing Guardsman Armor in the process. He then met up with Darkhawk and Spider-Man (Peter Parker) and together they battled the Brotherhood of Evil Mutants who wanted Portal to join them. Portal was then captured by the Brotherhood, and mind-controlled by Sauron into attacking Spider-Man, Darkhawk, and Sleepwalker. After the assembled heroes rescued Portal from Sauron's mind control, Portal escaped through a dimensional warp.

Portal returned to New York and reunited with Darkhawk who revealed that he was suffering from various complications that related to his armor, so Portal took over Darkhawks responsibilities as a local hero in Queens, for a short time. During this time Kistur turned up alive and in new armor. Now calling himself Overhawk he fought against Portal and Darkhawk alongside a large group of space marauders. After defeating Them Portal opened a dimensional warp to voyage to parts unknown.