NEW YORK: Vin Diesel still struggles over the loss of his friend and “Furious” co-star Paul Walker, so taking on the role of an immortal in the upcoming film “The Last Witch Hunter” helped him deal with his grief.

“Death was a huge theme last year,” Diesel told The Associated Press Friday. “There was something therapeutic about playing this role after going through (Walker’s death).” Diesel is no stranger to fantasy and sci-fi films, having starred in “The Chronicles of Riddick” series, “Babylon A.D.,” and “Guardians of the Galaxy,” but this one was special for him.

“The idea that someone immortal could be so melancholy. 2014 was a tough year for me in some ways — a lot of ways,” Diesel said, choking up before continuing. “Playing a character that was masking his sorrow — his loss — was very appropriate for the time, because that’s what I was doing in real life with the post-“Furious 7.”