The actor shot the film amid health issues.
"I think the character of Krrish has had the maximum impact on me than any other role that I have played in my life," said the actor at the launch of "Krrish 3" accessories here Saturday.
He plays the lead in the third instalment of the franchise that began with 2003 hit sci-fi movie "Koi... Mil Gaya".
"Through him I learnt that being a superhero is not really about wearing a mask or cape and flying through buildings....when I wear the jacket, there's a mental shift that happens and I feel unstoppable, unbreakable," he added and said that he used to forget about his pain.
Directed by Rakesh Roshan, the film is set for a Nov 1 release. It also stars Priyanka Chopra, Kangana Ranaut and Vivek Oberoi in pivotal roles.