In Avengers: Endgame, after Earth's Mightiest Heroes traveled back to the past to pluck the Infinity Stones out of the time stream, it was Bruce Banner's Smart Hulk who put on Tony Stark's Nano Gauntlet and snapped his fingers. The heroic act brought everyone whom Thanos had snapped away back, but it came at a cost: the power of the Infinity Stones permanently damaged the Hulk.
While answering questions for fans, co-directors Joe and Anthony Russo were asked why, despite his powerful healing factor, Hulk was left injured. "The Hulk has never come up against every Infinity Stone, in a Gauntlet, and the pure power of those Stones," Joe answered. "Thanos is nearly invincible and he did not heal either, so clearly when you wield the full power of the Infinity Stones it does irreparable damage to your being."
"If it doesn’t even kill you," Anthony added, referencing Tony Stark's fate at the end of the film.
Directed by Joe and Anthony Russo, Avengers: Endgame stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Jeremy Renner, Brie Larson, Paul Rudd, Don Cheadle, Karen Gillan, Danai Gurira and Bradley Cooper, with Josh Brolin as Thanos. The film is now available on Digital HD and arrives Aug. 13 on Blu-ray and 4K UHD.