The powers and mask of the super powered wrestler el Muerto have been passed down generation to generation. Each wrestler had to prove themselves to their oppressor, el Dorado, so that they could remain alive and keep their powers. When Marcus Estrada presented his son Juan Carlos to el Dorado, Juan Carlos cowered in terror, unwilling to fight him. Marcus Estrada sacrificed his life to try and save Juan Carlos. Out of respect for his father's courage, el Dorado granted Juan Carlos ten years to travel and to become brave, and then to duel a masked wrestler and unmask him.
Ten years later, el Muerto traveled to New York City and approached J. Jonah Jameson to set up a charity event: A wrestling match, in which el Muerto would fight Spider-Man. Jonah organized the match, hoping that el Muerto would defeat and unmask Spider-Man. El Muerto and Spider-Man both attended the match, and Spider-Man was confident he would easily defeat el Muerto. The tide turned, and el Muerto nearly unmasked Spider-Man. Reflexively, Spider-Man stabbed el Muerto with his stingers, injecting him with a paralyzing poison.
Spider-Man rescued el Muerto in the hospital when el Dorado came to claim his life. El Muerto came to and aided Spider-Man in defeating el Dorado. El Dorado still managed to escape before they managed to defeat him.