 In the mid-1950s Los Hermanos Shadow began a decade long rivalry with the top Rudo (villain) team of El Santo and Gory Guerrero, known as "La Pareja Atómica".After selling out arenas all around Mexico for their tag team matches El Santo and Black Shadow started to work singles matches against each other.The rivalry between Black Shadow and El Santo culminated in a Luchas de Apuestas, or mask vs. mask match, on November 7, 1952.