Карлито
He returned to WWC on April 4, 2015 to challenge for the Universal World Heavyweight Championship in the main event of Camino a la Gloria, but the match ended without a clear winner and Carlos "Chicano" Cotto retained. The series between both peaked in a cage match, which Hammet won to become the Universal Heavyweight Champion. At Aniversario 2015, he defeated Carly Colón to retain. During his reign as champion, Hammet would wear the belt in his appearances outside of Puerto Rico, carrying it with him in matches throughout the independent circuit of the United States and Canada. In an interview with WrestleZone, he explained that his intention was to give the title the foreign exposition that it had when Carlos Colón and Dory Funk feuded over it in the NWA territories and that he wanted people to feel "[that] this guy is going over to Japan with the belt and representing the island there. [...] This guy is going to Ecuador and he's representing there." On October 16, 2015, he debuted in Caution Wrestling Federation (CWF) by successfully defending the Universal Heavyweight Championship against masked luchador Zoom Driver, marking the first time that the title had been on the line in Mexican territory. On March 5, 2016, he lost the Universal Championship against Carlito.