Robert Grayson was the son of astrophycisist Dr. Horace Grayson, a German Jew who fled from Germany when Hitler began his rise to power in Germany. Seeking to flee the Nazi powers before a world war would take place, he begun work on a private spacecraft for both him and his infant son (his wife died in child birth).

Originally, Horace Grayson had planned simply to circle the moon until the crisis had passed, but after he was denied a loan from the bank, he started to search for an extra-terrestrial race by monitoring radio broadcasts. He found one such race of Eternals, a genetic off-shoot of humanity who left Earth thousands of years before and had found a home on Uranus in an ancient Kree city. They gave Grayson the knowledge to build his space ship, thus Grayson left the Earth just weeks after his loan application was rejection and before the war broke out.

The Graysons were greeted with open arms by the Eternals. They would be safe living under the tiny dome which contained the city, roughly 5 miles in diameter. They were also given small wrist devices which emitted anti-gravitons which allowed them to resist Uranus's intense gravity. While Robert Grayson was happy, being raised as an Eternal, he often wondered what it would be like back on Earth. So, with his father's blessing, he was given a more powerful set of wristbands, a ship called the "silver Bullet", and allowed to leave the colony. These wristbands contained the ability of absorbing sunlight and releasing it to blind his opponents. Robert Grayson would be become the hero of the 1950's known as Marvel Boy II.

For three years, Robert Grayson battled crime under the name of Marvel Boy, he even would answer the call to join John Woo's team known as the Agents of Atlas. It wouldn't be until he received a urgent summons to return with aid to the Uranian colony. Denied a loan for medical supplies, he eventually received enough funding for his return to Uranus.

He finally made his return to find the city in ruin only to learn the horrible truth that the city was actually a penal colony for rogue Eternals who had once attempted to conquer the Earth and the native Uranians. Banished by the Earth bound Eternals, the Uranian Eternals saw the Grayson's as a means to learn what had transpired on Earth since their banishment. The Uranians disagreed with this assessment, thus dooming the Uranian Eternals. The Uranian's, taking pity on Robert Grayson, offered to take him into their community, but he and the Eternals had lived as part of a communal organism, and hence, he would have to be reborn which would take decades to complete.

Before the Eternals' destruction, a duplicate of Robert Grayson was created and sent out to enact revenge on the banker who denied Robert Grayson's request for a loan. With a more powerful version of the bands, called "Quantum Bands", he faced the Fantastic Four. When he lashed out in rage against the Fantastic Four under the name 'Crusader', the bands disintegrated the duplicate, leaving just the Quantum Bands behind. These would be retrieved by Reed Richards, given to SHIELD, and passed down to Wendell Vaughn, the hero would take the name Marvel Boy and then Quasar.

Robert Grayson, feeling that he was not truly a part of the Uranian culture, eventually left until he received a distress call from his previous teammates of the Agents of Atlas. John Woo, of the team was near death, which Robert Grayson hurried to Earth to help, thus severing all ties between him and the Uranians. With the aid of John Woo, the Agents of Atlas once more became a team and would eventually become a powerful force for good.

Note: Just on the heels of Cosmos in Collision and just before the first battles were fought over the Infinity Gauntlet, Thanos interupted Eon’s funeral and fought Quasar, Thanos soon grew bored with the exchange and created four previous bearers of the Quantum Bands to destroy Eon’s champion. They were: The Stygian Starbender, Ree, Trantra of the Trill, and Robert Grayson also known as Marvel Boy.

It's unknown if this re-creation represented Bob Grayson or the "Crusader".