Mar-Vell came to earth as a spy for the Kree galactic empire. His mission, simply to observe the race that had bred warriors powerful enough to defeat the Kree sentries as well as Ronan the accuser. but soon things became quite different for Captain Mar-vell, his abilities on earth began to grow. Soon he had become so much more then just a warrior. His battles over the brief time he spent on our planet continually changed him. Soon he was granted a special uniform by the Kree Supreme intelligence ,as well as nega bands that allowed him to trade places with Rick Jones in the negative zone.

Soon after this he began the first battle that would mark him for greatness, the Kree - Skrull war. When this war ended , Captain Marvel had sacrificed his life force to Rick Jones, so that Rick could go on living. All involeved thought Mar-Vell had died, but that was not to be ! Mar-Vell was once again trapped in the Negative zone, but still very much alive. After several small skirmishes with minor villians, Mar-Vell came into contact with his one, true nemesis, Thanos of Titan ! A veritable god , who worshipped death herself as a lover. During this epic battle Mar-Vell became the Protector of the Universe entire through the power of Eon, a creation of Chronos, a Titan who had delved to deeply into science and paid the price of having his essence spread throughout reality.Mar-Vell defeated Thanos, but in a battle that included the Mighty Avengers that was almost lost, but for Mar-vells Cosmic Awareness. This powerful insight allowed Captain Marvel to strike at Thanos' true power source, the cosmic cube, thus rendering the gigantic and powerful titan insensate. Soon after Mar-Vell fought a minor villian named Nitro, the exploding man. Unbeknownst to Mar-Vell, in sealing off a ruptured canister of dealy gas with his gloved hand, he had inadvertantly contracted cancer, but this would not rear its head for some time.

Soon after Mar-Vell fought against the Lunatic Legion, as well as the Supreme Intelligence himself ! Then Captain Marvel returned to earth for a time again as he was brought into battle against Mercurio the four D man, a powerful enemy of Thors who wanted to invade our dimension.Not much after Mercurio was defeated Thanos returned. this time the Mad Titan fought against Mar-Vell, the Thing, Adam Warlock, the Avengers and Spider-Man in an epic struggle that rocked the galaxy. Once again the heores defeated the mad Titan by the skin of their teeth, thus saving the galaxy once more.

After this Mar-Vell returned to earth and battled on against Thor as well as Isaac, the living computer in an epic battle that was one of Captain Marvels finest hours. Not long after this Mar-Vells cancer began to show it's ugly face.He became gradually weaker as the greatest minds in the galaxy fought to save him. In the end all their powers and scientific as well as mystic might proved for naught. Mar-Vell passed away due to complications of cancer. Before his passing , the Skrulls, his most bitter enemies, gave him their medal of honor, But his own people branded him a traitor and an outcast. He died that way, but universally he was heralded as a hero by almost all other races.