Kinnikuman: New York Close Call! (1986)

Terryman, Robin Mask, and the other Justice Choujins are participating in a tournament in New York. Suddenly, Akuma Shogun (not the same as the guy from the series) arrives and defeats all of the Justice Choujins and absorbs their power... all except Kinnikuman (who was late for the tournament because he was busy eating gyuudon). Now Kinnikuman must defeat Akuma Shogun, whom now posseses the combined strength of all the Justice Choujins.