"There was a time when Banner became Smart Hulk in the first movie. It was a lot of fun, but it came at the wrong moment. It was an up, right when everyone else was down," Avengers co-writer Christopher Markus explained to the New York Times.
Added co-writer Stephen McFeely, that big moment would have happened in Wakanda as Earth's mightiest heroes assembled to ward off Thanos (Josh Brolin) and his invading alien army, who sought the sixth and final Infinity Stone.
"His arc was designed like, I'm not getting along with the Hulk, the Hulk won't come out. And then they compromise and become Smart Hulk," McFeely said.
The decision was made to instead hold off on the merged Banner Hulk until Endgame, where the new status quo is revealed after a five-year time jump.
"We were like, but he's Smart Hulk in the next movie. So that diner scene [in Endgame], was like, O.K., how do we smash right into that without scenes of him in a lab, gene-splicing?" Markus said.
Banner-slash-Hulk explains he began looking at Hulk as a cure and not a disease, revealing he spent 18 months in a gamma lab creating a compromise allowing the former enemies to coexist in one shared body.
"Oh, I wrote scenes in a lab. Now it's just him eating pancakes and I think it generally works," McFeely said. Added Markus, "The whole thing rides on [Paul] Rudd going, 'I'm so confused.'"
Ruffalo, who is notorious for accidentally giving away spoilers, revealed earlier this month he filmed a fake-out death scene for Infinity War, which ended with Banner suited up in the Hulkbuster armor when Hulk refused to show.
"For one take, I did disappear, and then the other one I didn't," Ruffalo told Yahoo.
"I was pretty sure it was gonna be me," Ruffalo added. "It's like Survivor. It's like, who's gonna get kicked off the island? And I probably should've. … It's like Project Runway for leakers."
Avengers: Endgame is now playing.
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