Ruffalo joined the cast reprising the role of Hulk from previous MCU films , which allowed elements of the 2006 comic storyline `` Planet Hulk '' to be adapted for Ragnarok , along with elements of `` Marvel Super Hero Contest of Champions '' .
Ragnarok adapted elements of `` Marvel Super Hero Contest of Champions '' once Ruffalo joined the cast for Thor : Ragnarok as Hulk .