Most things in space are the same. Earth, not so much.
Captain America: An airforce captain during ww2 who would later help China and West East Asia repel Japanese invasion and a living legend amongst them, but less respected in his country. Eventually, his plane was shot down but a dragon god bounded with him and finally resurrected him in modern times. Though he lacks a traditional shield, he has a superior version of Iron Fist power, bullet proof vest and a dragon scaled shield which he can summon at will. In this universe Steven Rogers was never given the serum but become a captain through his bravery regardless, and died as a regular agent of Shield.
Iron Woman: A defect Hydra Scientist eventually realized their imposed idea of Racial Purity was not worth his time. He eventually join Stark Industry, but got assassinated by Hydra years later. His daughter, recently graduated from MIT engineering, decided to use her father's toys to get revenge but learn to become more heroic.
Hulk: Abomination, who willingly participate in military research in hope of becoming of use for his country, but become disfigured and ends up as an anti hero.
Thor: In this version the Norse Gods are dead after centuries of ceased worship due to Christian take over. Instead Storm becomes worshipped as Thor. This worship bring back the Asgardians who was initially enraged by her title, by ultimate accept her as the new Thor and granted Mjolnir.
Spider Man: A more sinister Peter Parker decided to get revenge on Flash Thompson who was given to Oscorp as an experiment, but he bounded with the Symbiote, and eventually Flash learns to become more heroic after hearing people genuinely praise him for saving someone, but he still has a few habits from his days as a bully.
Starlord (Gamora): During Thanos' early travels, he manage to impregnate the younger Princess of Spartax, who give birth to the child who then sent away the girl out of fear for her life, but the rocket had an accident. The Guardians, led by Yondu, found the baby girl on the failing ship.
Captain Marvel: Marvell 's great great grand mother were among the last of Kree Experiment before the inhumans repelled the aliens, and she was taken back to Kree capital. Marvell would eventually return to Earth to recover the data on the research and found out she was part inhuman, and her powers awakened due to unintended contact with Terragen Mist which make her lose more of her Kree traits. Marvell would eventually join a by the time weak Shield and eventually founded Sword to shelter herself from the wrath of Supreme Intelligence.
Fantastic Four: Beast, Night crawler, Cyclopse and Rogue were astronauts working for Sword, and their mutation was activated as their ship gets burned up after a stream of Radioactive plasma nearly burned up their ship.
Dr.Strange: After Mysterio burned his hand during a special effect test, he went to seek Dr.Strange who refused to help him, which lead Mysterio to Tamar Raj, where he learns the mystic arts and become the defender of the realm.
Need help with Ant man. Maybe just make Ultron good in this one or make Scott Lang the scientist too?