Tyrannus

Tyrannus is a human villain and the ruler of an unidentified subterranean race. He was banished to "the center of Earth" centuries ago by Merlin—for reasons that are unclear, but likely related to his despotic leanings—but happened to discover the Fountain of Youth underground and has sustained himself on its contents since. He also claimed rule over a scientifically advanced race that lives there, aiming to use their skills to assemble a force to conquer the surface world. He also claims to have been a master of black magic since medieval times. His history with Merlin suggests that he is approximately 1,500 years old. Tyrannus enacted his desire to rule the surface world by kidnapping Betty Ross in 1963, but the Hulk and Rick Jones followed him underground and rescued her.