10 Scrapped Ideas For Star Trek: Enterprise Season 5
2. Requiem For A Flint
Requiem For Methusaleh was a third-season episode of the Original Series, featuring the character of Flint, as he was then known. He was originally a human male, though he was immortal, living through thousands of years of human history. Along the way, he lived many, many lifetimes and even adopted the identities of some of Earth's greatest names.
He lived as King Solomon, Alexander the Great, Lazarus (said to be the basis of the story of resurrection), Leonardo da Vinci, and Johannes Brahms. Through all of this time, he saw the barbarity of human nature so, when he was finally able to do so, he left the planet to reside on Holberg 917G. It was there that the crew of the Enterprise encountered him, and Dr. McCoy confirmed that he was, finally, dying.
Manny Coto felt that he was an underutilized idea that deserved to be developed. He could easily come into contact with the crew of Enterprise without spoiling the timeline, as he had often posed as other identities. He could even reveal himself, requesting that his true nature be kept a secret. It was also possible that the Vulcans knew of him, as they wouldn't necessarily reveal their findings to Starfleet right away.
What is known is that he was at least aware of the birth of the Federation, meaning he could have been active on Earth around this time. There is nothing to suggest that he couldn't have been a key player in the drafting of the Federation Charter itself, which would have brought him into direct contact with Jonathan Archer.