It has been theorised that the Forever Man is one of the first Mutant on Earth. An immortal who when he dies and is born again from his own ashes with no memory of his former lives. He lived many lives going back at least as far as Ancient Egypt. He has claimed to have had over 10,000 names in that time.
Morgan MacNeil Hardy
The Forever Man was in San Francisco during the 1906 Earthquake and was killed and later resurrected in the flames. Now a teenager again he was given the name "Morgan MacNeil Hardy" and considered the city his home and wished to return it to it's prominence before the quake.
He became a millionaire had helped helped rebuild his city. He became ashamed at the "degeneration of manners and mores" in the following decades, specially since the beginning of World War I. Hardy tried to foster a movement in favor of traditional values, but he failed. He adopted the son of his chauffeur when he died Clifford Michaels. He taught teach him of the morals and values of the first years of the 20th century and, to do so, he restricted Clifford's access to the "outside world". His teaching warped the young man mid turning him into the radical Turner D Century.
Century caused havok across the city attacking the people and destroying many establishments. Spider-Woman tracked him to Hardy's estate, where Hardy was shocked to learn what his "son" had been up to. The two battled destroying the replica town he had built. He convinced his son to stop and the two stayed together to watch the small town burn.
He decided to make up for what his adopted son had done and planned to remake the country in his image. He found various telepathic people (Ursula Richards, Phillip le Guin, Eva Krauss, Harold Becker) and attached them to a device called the Telepathic Augmenter. He used their powers to re-write reality itself. But the process had it's limits and they began to manipulate reality to match their views. Ursula used her powers to call Captain America for help. Hardy hooked himself to the machine and tried to wipe Cap from existence but being a symbol of the country he caused the US to disappear as well. Devastated he attempted to reverse the process being blown with the machine.
He returned to life and now was able to remember all his past lives. The knowledge drove him insane, and he hated that he would always be force to start over with nothing. Eventually, he drove a spaceship into the sun, but that just caused him to die, be reborn, and die again every second. He finally was reborn as a plasma create of solar fire, and returned to Earth, where the Avengers defeated him. He was reborn again as a young boy, with no memory of his past. However, the Avengers wondered if he was faking.