At the Television Critics Association summer press tour on Sunday, Buck explained to IGN that the character was specifically set up to be a foil for the rest of the Defenders.
"But do you really want four dark, brooding Defenders? ... We created him to fit into that world and be a counterpart to some of the others," Buck said. "Perhaps people were not aware that there were reasons for creating a character with that sort of specific [personality]."
Buck also explained that The Defenders' Douglas Petrie and Marco Ramirez received only the smallest bit of input on Danny's depiction for the upcoming series.
"I gave them whatever input I possibly could, but Defenders is entirely their creature," Buck said, adding that there was a lot he didn't get to do with the character in Iron Fist's first season.
Jeph Loeb's San Diego Comic-Con announcement that Buck would be leaving Iron Fist to take on The Inhumans means that Buck won't get to explore his other ideas for Danny, but Buck is confident that the new showrunner, Raven Metzner, will do a good job.
"They found a great showrunner to take over Iron Fist, Raven. It's in his hands now. He's a terrific writer and he's going to do a great job," Buck said.
The Defenders debuts on Netflix on August 18th.