Vin Diesel revealed that Fast & Furious 7 became the most challenging movie he has made throughout his career.

Diesel sat down with Terri Seymour from Extra and he talked about finishing the film with Walker’s brothers Cory and Caleb.

“On some levels it was very cool to know his brothers were supporting this and wanting to help. On another level, they triggered memories, unintentionally at times. There’s no one like Paul Walker and there was only one Paul Walker,” Diesel said. He also revealed that it was difficult to be in mourning while having to pretend that Walker is still alive for the movie’s sake.

Vin Diesel talks about finishing Fast & Furious 7 without Paul Walker

When Walker died in November, filming of Fast & Furious 7 had to be stopped. It even came to a point where the producers contemplated whether to finish the movie. However, they decided to finish what they started, as Walker would have wanted it to be finished.

The first time Diesel got back on set after Walker’s death, he revealed that he went through three boxes of tissues while filming a scene. “I am supposed to be in killer mode, but just being in the vehicle that was synonymous with Paul and myself, it was so hard to get through,” he said.

Diesel said that finishing the film with Walker’s brothers was a bit strange. “It’s very, very weird. The good thing is, because we took all the time, the movie is a true testament to everyone coming together and wanting to honor both the saga and our brother, and there’s something very beautiful about that,” Diesel said.

Caleb and Cody Walker on the set of #FF7 as they work as stunt for their brother #PaulWalker. http://t.co/Qk0UZpbXgf pic.twitter.com/BbAKParWLl

— elCinema.com (@elCinema) April 22, 2014

Aside from Fast & Furious 7, Diesel also talked about his upcoming movie Guardians of the Galaxy where he plays Groot, a tree-like creature and superhero in the Marvel Universe. “I am really fortunate that I have both of these movies and there’s something very, very healing about playing a character like Groot that celebrates life after a tragedy like the one that happened,” he said.

Image via YouTube