Near the end of 2005 Guerrero helped Atlantis during a match, thus turning Atlantis "rudo" for the first time in his career. When he joined "Los Guerreros" the group changed their name to "Los Guerreros de la Atlantida" (the Warriors of the Atlantis). In May 2006, Guerrero won CMLL's annual "International Grand Prix" tournament that featured wrestler for Mexico, Japan and the United States. later on "Los Guerreros" ejected Rey Bucanero from the group, with Guerrero and Tarzan Boy tearing up Bucanero's tights, signifying he was no longer a member of the group. On July 14, 2006 Rey Bucanero defeated Guerrero for CMLL World Light Heavyweight Championship, ending the reign after 3 and a half years.