Romulus Augustulus (Romulus the "little Augustus") lived during Roman times. He is named after Romulus Augustulus (r. 475-476), a child emperor of the Western Roman Empire. He has claimed to be this emperor rendered immortal. He was known as Tyrannus. His codename is Latin for "tyrant", "absolute ruler" and "usurper". The term originates from the Greek term tyrrannos/turranos (τύραννος) for a ruler who seizes control of a city-state and rules in an absolute manner. The word originally had no value judgement for these men. A couple of centuries later, Plato and Aristotle defined it as "one who rules without law, looks to his own advantage rather than that of his subjects, and uses extreme and cruel tactics -- against his own people as well as others".
In any case, Tyrannus was an exceptional scientist far ahead of his peers. He claimed he was a sorcerer and used his scientific knowledge to support his claims.
Merlin exiled Tyrannus to Subterranea; a place that contained a network of caves and tunnels miles below the surface of the Earth. There was already a race of orange-skinned semi-humanoid race of beings living in Subterranea. These semi-humanoid beings were primitive and it was an easy thing for Tyrannus to convince them he was a superior being worthy of being worshiped by them. They accepted Tyrannus as their new master and were willing to serve him. While Tyrannus was living in Subterranea he found a pool that contained a liquid. Tyrannus suspected the liquid had special powers so he began to drink it. Tyrannus drank the liquid regularly and the liquid maintained his youth for centuries.
The Deviants lived in Subterranea and were worshipped by the beings living in Subterranea before Tyrannus came to live there. Tyrannus found examples and records of technology left behind by the Deviants. Tyrannus worked on and studied the works of the Deviants for centuries and his skill and knowledge as a scientist helped him to understand and improve on the scientific discoveries of the Deviants.
Tyrannus’s goal and plan was to someday conquer the surface world. Finally he felt he was ready to try to achieve his desire. He felt the technology at his disposal and with the help of the Subterraneans he will able to take over the surface world.
Tyrannus makes several unsuccessful attempts to conquer the surface world but something happens that he was not counting on. There is now a new arrival in Subterranea named the Mole Man. The Mole Man also has forces at his disposal and Tyrannus will have to deal with those forces and the Mole Man before he can continue with his plan to conquer the surface world.
Tyrannus needed several things done so he came up with a plan. He persuades Betty Ross to come into the underground world and then kidnaps her. When the Hulk discovered that Betty had been kidnapped he went to get Betty back. Tyrannus made a deal with the Hulk, Tyrannus would give Betty to the Hulk if the Hulk would complete some tasks first. The Hulk completes the tasks and Tyrannus gives Betty to the Hulk.
After this Tyrannus forsakes his human form and joins with an enormously powerful cobalt energy "flame." Tyrannus' consciousness has power over the Flame after he merges with it. However the flame comes from a piece of machinery. The Hulk destroyed the machine that produced the flame and this resulted in the flame and the consciousness of Tyrannus being hurled deep into outer space.
The liquid that Tyrannus drank was actually from the fountain of youth. This caused him not to age.