Born in the year 2142 in the slums of the great Martian city of Olympus, Sebastian never knew his father and his mother died to illness when he was just 12. Living alone in the slums Sebastian, know as Seb at this time, survived by stealing from and scamming the more well off citizens of Olympus. His life continued this way until he caught the unwanted attention of the local mafia. Seb refused to join them despite threats to his own life, so to avoid being killed he joined the martian military at the age of 17 with his life long friend Sam Blaine.

2163, War breaks out between the United Solar System Federation, or U.S.S.F. for short, and the outer rim mining colonies. Sebastian and Sam were deployed as a first officer and chief officer, respectively, aboard the U.F.S. Angler, a small 30 persons fast ambush vessel. During the 4 year war the Angler accumulated the most confirmed kills of enemy vessels at 47.

In the last and largest battle of the war over the martian satellite Deimos the Angler took critical damage and performed an emergency landing on the moon. 20 crew members died in that battle including the captain and Sam, Sebastian survived but lost his left hand. As the, now previous, first officer Sebastian was now the captain. While the battle raged on for the next 7 weeks Sebastian and his remaining crew managed to repair the angler with the help of local salvagers, but for unknown reasons the Angler deserted the battle and military before it was over.

In the year 2167 following the last battle, which would be remembered as the Great Battle of Deimos, the war ended with the U.S.S.F. destroying the last of the colonies forces. The entire crew of the Angler, as well as Sebastian, were thought to have died and were honored as war heroes for their achievements throughout the war.

Sebastian Flint was last seen in 2172 aboard the now infamous pirate ship The Anguisher raiding U.S.S.F. trade ships in lawless asteroid belt. Now known as Captain Flint The Steel Claw, Sebastian is the most wanted men in the solar system.