Colonel Bahamut is the main antagonist of Contra: Hard Corps and the main protagonist of Hard Corps: Uprising, which is the prequel to the Contra series. He first fought the Commonwealth Empire and its leader Tiberius during the events of Hard Corps: Uprising in the year 2613 and he was a war hero during the Alien Wars, but sometime later, he planned a coup'd'etat to overthrow the government. While the coup was crushed, Bahamut fled and went into hiding. He later resurfaced to start a new uprising with the help of the Alien Cell.
Depending on the decisions made by the player, the fate of the Colonel changes.
- If the player decides to pursue Deadeye Joe and Surrender and Fight Later, the Colonel will complete his plans of using the Alien Cell in his Space Station, destroying his headquarters on Earth. When the player reaches the station, Bahamut reveals his final weapon "Big Magnum" which he plans to use to destroy the world. His plan is thwarted by the Hard Corps, but a price has to be payed. The Space Station is destroyed with the player and Bahamut who says "Ugh! Just one more step and I would had been a God!" as his last words, just seconds before the station explodes.
- If the player decides to pursue Deadeye Joe and Fight to the End, the experiments with the Alien Cell will fail since it Bahamut's minions decided to continue the experiment without Geo Mandrake's supervision. As the alien infestation takes control of the Headquarters, the Hard Corps takes control of the situation, just to see Bahamut flying away in his helicopter, who promises that the next time they met the outcome will be different.
- If the player decides to save the Laboratory and Surrender and Fight Later, Bahamut will merge with the Alien Cell to became a superbeing, however the fusion turns out to be too much for the Colonel who mutates in two different monsters. When the Colonel-Alien Cell Hybrid is destroyed, his fortress crumbles, putting an end to the Colonel's plans for good.
- If the player decides to save the Laboratory, Fight to the End, and Agrees to Join forces with the Colonel, he will became the most evil Dictator of all time, sending mankind to an age of darkness and gloom.
- If the player decides to save the Laboratory, Fight to the End and Refuses to join forces, the Colonel will fight to the player, only to be defeated by the Hard Corps, before dying he tells the Hard Corps that a Missile with the Alien Cell will be launched at the moment of his death in a final plan to see the world in the flames of hell.
- While he shares his name with the main protagonist of Hard Corps: Uprising, the producers stated in an interview that it could be a different person entirely.