In June 1997, Castillo made his move to the World Wrestling Federation, as a member of the Los Boricuas stable, which was led by Savio Vega.

Castillo mainly competed in tag team matches with other members of the group José Estrada Jr., Miguel Pérez, and leader Savio Vega.

In summer 1998, Castillo became a jobber, competing on Shotgun, losing to superstars; featuring a young Edge, X-Pac and Dan Severn.

After being released by the WWF Castillo joined the newly formed International Wrestling Association (IWA) in Puerto Rico and reunited with Los Boricuas Savio Vega and Miguel Perez.

His retirement match happened on April 9 at GZW's Accion Sin Limites, where he and Demolition X defeated Agente Bruno and El Profe.